From patchwork Mon Apr 29 20:27:50 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647672 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6BAD213AA5D; Mon, 29 Apr 2024 20:28:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422507; cv=none; b=kV5aoDYhTMxmIl6Hor5U5MXOLcZdkzlpNJOvotadjw3wLHH+jlm9cp1pcfo2NRjq++RP4aK0YsGxmvCmYPlWDmqBEjbzjocfuOeCQOPKVj3d7ZSo0hGicwqOKrzEzPisoQFe21P7TM9urJe7YDMUqIMSjoyxRZxyfNEdNdFnBwY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422507; c=relaxed/simple; bh=4qxQrwlnc+5YPOt4IlE0P++QkRidh610wXXOVgj1Ql8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=itLtHiANGwpvP77PLOhyt/mech6bgcCCZKrBsyf5xD8D5s3PfS6JrRHjSdsc1z6wvRT4Aj67kQBSOkwZd0DP3MVXkvAKRLFmrSGdCSKOllbbwHm6Dz6egg1tLH6eN5dGVJf0F29vU9Z2IU1n8CBQL7q/pSJEHkMg4JnlFfcKutM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=iP4idAs5; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="iP4idAs5" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422505; bh=4qxQrwlnc+5YPOt4IlE0P++QkRidh610wXXOVgj1Ql8=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=iP4idAs5UflWNZSmLFSVnzASL2r247Ql+2g57DF24mWsmp0J7TeseDkk96gTDRXiZ Xr+csCLR24+6n49FfFnc032SAVBVdq78UCtnVzQwlgVJtgEOvrcVJf07PRDwFWcaQM EMra2FmU+hkfIaf2AswSlmK2sNTXZT0vw5CrgtUw= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id CA54D1285D65; Mon, 29 Apr 2024 16:28:25 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id T32Q_sndhkbk; Mon, 29 Apr 2024 16:28:25 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 2684D12819F3; Mon, 29 Apr 2024 16:28:25 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 01/22] tpm: Remove unused tpm_buf_tag() Date: Mon, 29 Apr 2024 16:27:50 -0400 Message-Id: <20240429202811.13643-2-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Jarkko Sakkinen The helper function has no call sites. Thus, remove it. Signed-off-by: Jarkko Sakkinen Signed-off-by: James Bottomley --- include/linux/tpm.h | 7 ------- 1 file changed, 7 deletions(-) diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 4ee9d13749ad..6588ca87cf93 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -358,13 +358,6 @@ static inline u32 tpm_buf_length(struct tpm_buf *buf) return be32_to_cpu(head->length); } -static inline u16 tpm_buf_tag(struct tpm_buf *buf) -{ - struct tpm_header *head = (struct tpm_header *)buf->data; - - return be16_to_cpu(head->tag); -} - static inline void tpm_buf_append(struct tpm_buf *buf, const unsigned char *new_data, unsigned int new_len) From patchwork Mon Apr 29 20:27:51 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647673 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 66B7413AA5D; Mon, 29 Apr 2024 20:28:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422518; cv=none; b=Ye9m9mxE3gSo82ou5JZwlGsQfz30xrd2W3ZqanWj/7v4LgYjI1Vq291MgsQQ/+IqESeyiye9+G9paPDv8Uw/+jvNJV6nKoKbEmwrSBr4hByLnla/pZYP37bPNzXGkHHHbs8zJ/iufC21qhMd0o1dY9i4tIKH1nJzBI/URpheILI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422518; c=relaxed/simple; bh=Wyr9ED2k1aUHQpzYMoWHKIOFQOSaFOeR+LbNUxV2M34=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=PXUQaY2XjlFnhxfX9qxZG+3lt+6qQb/eRjiHw0zmrh5LIb86vl5/ZEdyvsxxRJtqG4HP5e5FCU16l5f0LupDRx6X6PJXG+StT//sJ/CjtghoQshRcYBKsh7/Up5atln9KjjYhU81S4RkLoAp1NHG+c/E4MKoWixnQO+dN7OBdaA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=pPL41kRr; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="pPL41kRr" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422516; bh=Wyr9ED2k1aUHQpzYMoWHKIOFQOSaFOeR+LbNUxV2M34=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=pPL41kRrTjK68lUz4vYG+a7nqwuamXRFFya4XyyAXwYi143gr7QpFNBpHi8Rg5ScX dSQsbXC4K/x3Zzqxcyo4urfZbGBrva9oIIUmxHF0sffHKa/ywT7DdkhOefhhjkA8nH sLbD2VZ1kSi1RdNZxJZOCuNaEyX6oRBK88M3gCkg= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id C80A71281D87; Mon, 29 Apr 2024 16:28:36 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id 5ToJYGgs_Si0; Mon, 29 Apr 2024 16:28:36 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 33D1612819F3; Mon, 29 Apr 2024 16:28:35 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 02/22] tpm: Remove tpm_send() Date: Mon, 29 Apr 2024 16:27:51 -0400 Message-Id: <20240429202811.13643-3-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Jarkko Sakkinen Open code the last remaining call site for tpm_send(). Signed-off-by: Jarkko Sakkinen Signed-off-by: James Bottomley --- drivers/char/tpm/tpm-interface.c | 25 ----------------------- include/linux/tpm.h | 5 ----- security/keys/trusted-keys/trusted_tpm1.c | 14 +++++++++++-- 3 files changed, 12 insertions(+), 32 deletions(-) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 757336324c90..f940045a014e 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -342,31 +342,6 @@ int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, } EXPORT_SYMBOL_GPL(tpm_pcr_extend); -/** - * tpm_send - send a TPM command - * @chip: a &struct tpm_chip instance, %NULL for the default chip - * @cmd: a TPM command buffer - * @buflen: the length of the TPM command buffer - * - * Return: same as with tpm_transmit_cmd() - */ -int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen) -{ - struct tpm_buf buf; - int rc; - - chip = tpm_find_get_ops(chip); - if (!chip) - return -ENODEV; - - buf.data = cmd; - rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to a send a command"); - - tpm_put_ops(chip); - return rc; -} -EXPORT_SYMBOL_GPL(tpm_send); - int tpm_auto_startup(struct tpm_chip *chip) { int rc; diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 6588ca87cf93..d9d645e9c52c 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -422,7 +422,6 @@ extern int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx, struct tpm_digest *digest); extern int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, struct tpm_digest *digests); -extern int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen); extern int tpm_get_random(struct tpm_chip *chip, u8 *data, size_t max); extern struct tpm_chip *tpm_default_chip(void); void tpm2_flush_context(struct tpm_chip *chip, u32 handle); @@ -443,10 +442,6 @@ static inline int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, return -ENODEV; } -static inline int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen) -{ - return -ENODEV; -} static inline int tpm_get_random(struct tpm_chip *chip, u8 *data, size_t max) { return -ENODEV; diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c index aa108bea6739..37bce84eef99 100644 --- a/security/keys/trusted-keys/trusted_tpm1.c +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -356,17 +356,27 @@ static int TSS_checkhmac2(unsigned char *buffer, */ int trusted_tpm_send(unsigned char *cmd, size_t buflen) { + struct tpm_buf buf; int rc; if (!chip) return -ENODEV; + rc = tpm_try_get_ops(chip); + if (rc) + return rc; + + buf.flags = 0; + buf.data = cmd; dump_tpm_buf(cmd); - rc = tpm_send(chip, cmd, buflen); + rc = tpm_transmit_cmd(chip, &buf, 4, "sending data"); dump_tpm_buf(cmd); + if (rc > 0) - /* Can't return positive return codes values to keyctl */ + /* TPM error */ rc = -EPERM; + + tpm_put_ops(chip); return rc; } EXPORT_SYMBOL_GPL(trusted_tpm_send); From patchwork Mon Apr 29 20:27:52 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647674 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9D2A513AA5D; Mon, 29 Apr 2024 20:28:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422529; cv=none; b=Q3QYmZLEtAWlI40j9opNQ0bfh5ahKe7ENpRliaSClRxMwW/pplsndIPihCSpMCSAS+Fhb0AAKF00B6l4J82ipjTsC0GPU4pcZEnfunTLrIa62FCtQIWgvclKLoJFQtJZn5lHFTFATm1Yus1g3U81KPmmL/lTRyBy3hPa+snVR1c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422529; c=relaxed/simple; bh=4DImhrudZ9znlmNF6meZrbdL9Csk0OqVMWjaSO93PrE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=AObm/Kx+ub2E07kMu4UEZGjZaWgE9VGd8d2rYQwHmT2HgLAgBEu3xLplgcNh2yeFJwkpI70i5/s5iqYhhowhhKP4xPl0Ilh5QeldWm1MA3KspX6AVK8h+qrJFDWAm5V5osL3DydsMP90Av49Rn1I6+a0VgGCMPIamc7Rowf9cC4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=NwJc2Br2; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="NwJc2Br2" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422527; bh=4DImhrudZ9znlmNF6meZrbdL9Csk0OqVMWjaSO93PrE=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=NwJc2Br2Twitg+j4XcRGQCsX4Y3yBxwssEqiiNsu541yoknDucGWhZQ+PbQLZ4sw7 mZV55vFY6+oRlZ0I++qKCxyAoQhQMd8YR4FqP/mTtrDr17Am4/X834duM7JFvR4PSV Vw6/PW40txKU61WN2CBlp5MSEZIjppQ+BOYDNeGQ= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 0A85412819F3; Mon, 29 Apr 2024 16:28:47 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id 3uW1r-0Lfk6n; Mon, 29 Apr 2024 16:28:46 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 711A71281ED0; Mon, 29 Apr 2024 16:28:46 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 03/22] tpm: Move buffer handling from static inlines to real functions Date: Mon, 29 Apr 2024 16:27:52 -0400 Message-Id: <20240429202811.13643-4-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 separate out the tpm_buf_... handling functions from static inlines in tpm.h and move them to their own tpm-buf.c file. This is a precursor to adding new functions for other TPM type handling because the amount of code will grow from the current 70 lines in tpm.h to about 200 lines when the additions are done. 200 lines of inline functions is a bit too much to keep in a header file. Signed-off-by: James Bottomley Signed-off-by: Jarkko Sakkinen Signed-off-by: James Bottomley --- drivers/char/tpm/Makefile | 1 + drivers/char/tpm/tpm-buf.c | 87 ++++++++++++++++++++++++++++++++++++++ include/linux/tpm.h | 80 ++++------------------------------- 3 files changed, 97 insertions(+), 71 deletions(-) create mode 100644 drivers/char/tpm/tpm-buf.c diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile index 0222b1ddb310..ad3594e383e1 100644 --- a/drivers/char/tpm/Makefile +++ b/drivers/char/tpm/Makefile @@ -15,6 +15,7 @@ tpm-y += tpm-sysfs.o tpm-y += eventlog/common.o tpm-y += eventlog/tpm1.o tpm-y += eventlog/tpm2.o +tpm-y += tpm-buf.o tpm-$(CONFIG_ACPI) += tpm_ppi.o eventlog/acpi.o tpm-$(CONFIG_EFI) += eventlog/efi.o diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c new file mode 100644 index 000000000000..96cee41d5b9c --- /dev/null +++ b/drivers/char/tpm/tpm-buf.c @@ -0,0 +1,87 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Handling of TPM command and other buffers. + */ + +#include +#include + +int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal) +{ + buf->data = (u8 *)__get_free_page(GFP_KERNEL); + if (!buf->data) + return -ENOMEM; + + buf->flags = 0; + tpm_buf_reset(buf, tag, ordinal); + return 0; +} +EXPORT_SYMBOL_GPL(tpm_buf_init); + +void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal) +{ + struct tpm_header *head = (struct tpm_header *)buf->data; + + head->tag = cpu_to_be16(tag); + head->length = cpu_to_be32(sizeof(*head)); + head->ordinal = cpu_to_be32(ordinal); +} +EXPORT_SYMBOL_GPL(tpm_buf_reset); + +void tpm_buf_destroy(struct tpm_buf *buf) +{ + free_page((unsigned long)buf->data); +} +EXPORT_SYMBOL_GPL(tpm_buf_destroy); + +u32 tpm_buf_length(struct tpm_buf *buf) +{ + struct tpm_header *head = (struct tpm_header *)buf->data; + + return be32_to_cpu(head->length); +} +EXPORT_SYMBOL_GPL(tpm_buf_length); + +void tpm_buf_append(struct tpm_buf *buf, + const unsigned char *new_data, + unsigned int new_len) +{ + struct tpm_header *head = (struct tpm_header *)buf->data; + u32 len = tpm_buf_length(buf); + + /* Return silently if overflow has already happened. */ + if (buf->flags & TPM_BUF_OVERFLOW) + return; + + if ((len + new_len) > PAGE_SIZE) { + WARN(1, "tpm_buf: overflow\n"); + buf->flags |= TPM_BUF_OVERFLOW; + return; + } + + memcpy(&buf->data[len], new_data, new_len); + head->length = cpu_to_be32(len + new_len); +} +EXPORT_SYMBOL_GPL(tpm_buf_append); + +void tpm_buf_append_u8(struct tpm_buf *buf, const u8 value) +{ + tpm_buf_append(buf, &value, 1); +} +EXPORT_SYMBOL_GPL(tpm_buf_append_u8); + +void tpm_buf_append_u16(struct tpm_buf *buf, const u16 value) +{ + __be16 value2 = cpu_to_be16(value); + + tpm_buf_append(buf, (u8 *)&value2, 2); +} +EXPORT_SYMBOL_GPL(tpm_buf_append_u16); + +void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value) +{ + __be32 value2 = cpu_to_be32(value); + + tpm_buf_append(buf, (u8 *)&value2, 4); +} +EXPORT_SYMBOL_GPL(tpm_buf_append_u32); diff --git a/include/linux/tpm.h b/include/linux/tpm.h index d9d645e9c52c..bb0e8718a432 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -326,77 +326,15 @@ struct tpm2_hash { unsigned int tpm_id; }; -static inline void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal) -{ - struct tpm_header *head = (struct tpm_header *)buf->data; - - head->tag = cpu_to_be16(tag); - head->length = cpu_to_be32(sizeof(*head)); - head->ordinal = cpu_to_be32(ordinal); -} - -static inline int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal) -{ - buf->data = (u8 *)__get_free_page(GFP_KERNEL); - if (!buf->data) - return -ENOMEM; - - buf->flags = 0; - tpm_buf_reset(buf, tag, ordinal); - return 0; -} - -static inline void tpm_buf_destroy(struct tpm_buf *buf) -{ - free_page((unsigned long)buf->data); -} - -static inline u32 tpm_buf_length(struct tpm_buf *buf) -{ - struct tpm_header *head = (struct tpm_header *)buf->data; - - return be32_to_cpu(head->length); -} - -static inline void tpm_buf_append(struct tpm_buf *buf, - const unsigned char *new_data, - unsigned int new_len) -{ - struct tpm_header *head = (struct tpm_header *)buf->data; - u32 len = tpm_buf_length(buf); - - /* Return silently if overflow has already happened. */ - if (buf->flags & TPM_BUF_OVERFLOW) - return; - - if ((len + new_len) > PAGE_SIZE) { - WARN(1, "tpm_buf: overflow\n"); - buf->flags |= TPM_BUF_OVERFLOW; - return; - } - - memcpy(&buf->data[len], new_data, new_len); - head->length = cpu_to_be32(len + new_len); -} - -static inline void tpm_buf_append_u8(struct tpm_buf *buf, const u8 value) -{ - tpm_buf_append(buf, &value, 1); -} - -static inline void tpm_buf_append_u16(struct tpm_buf *buf, const u16 value) -{ - __be16 value2 = cpu_to_be16(value); - - tpm_buf_append(buf, (u8 *) &value2, 2); -} - -static inline void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value) -{ - __be32 value2 = cpu_to_be32(value); - - tpm_buf_append(buf, (u8 *) &value2, 4); -} +int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal); +void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal); +void tpm_buf_destroy(struct tpm_buf *buf); +u32 tpm_buf_length(struct tpm_buf *buf); +void tpm_buf_append(struct tpm_buf *buf, const unsigned char *new_data, + unsigned int new_len); +void tpm_buf_append_u8(struct tpm_buf *buf, const u8 value); +void tpm_buf_append_u16(struct tpm_buf *buf, const u16 value); +void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value); /* * Check if TPM device is in the firmware upgrade mode. From patchwork Mon Apr 29 20:27:53 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647675 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5CF40142E6A; Mon, 29 Apr 2024 20:28:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422539; cv=none; b=Fay9X3RyEZ9cTlXgiN+d0wSUZdaObFnKCEFJOvFGXeI7+Z6/xgiEyO1qjlSsVuXl2hwhkcVxOt0V07IL0B9fcBWYTz1wKO7sFGNEDFTULes3MHnX3uA8PPOm0w79jhl9aJ55Ghsc5Zs/VwjfUR/h1CsndSB+WPhQOk2yv16rtgI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422539; c=relaxed/simple; bh=I6Gvq5Hf1pNtrzsESMyjfVDjeg4UkqOIhC0QdXTOBag=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=A3MWwIDHKPKIIiknFTUkJ0cZjxlaXIL+4+AAuFvLnnx1l1duMY5Hxx3fVEQ64gHZwBB2LEy7H6MAScyz8XeoRzsMYSs9Q/T41qyj1CX2duIBIzk9hQdaRStqY+1DnAhEpc09VvABgHzl0t/XCwBbVaC1nO6fx6OA7PkFbZ2IR3I= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=CGKULgtG; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="CGKULgtG" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422537; bh=I6Gvq5Hf1pNtrzsESMyjfVDjeg4UkqOIhC0QdXTOBag=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=CGKULgtGgUj6zqKMUiE7bJzfk2cy+QOeNeUMv7YWNuqKztx+j3AarZLaITzu3dd4s V4XTYnJ7P5LoMzvbVrjkniS/ohb7rY8gK80N86OgmX9SZpB0RdM080IYN9nXjNYyge F8P7sl+uknMrjltrjYUK0+60Xq+iD7DsJ5+g7V7w= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id C1F8F1281D87; Mon, 29 Apr 2024 16:28:57 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id 68gaViiR2t3Z; Mon, 29 Apr 2024 16:28:57 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 263B112819F3; Mon, 29 Apr 2024 16:28:57 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 04/22] tpm: Update struct tpm_buf documentation comments Date: Mon, 29 Apr 2024 16:27:53 -0400 Message-Id: <20240429202811.13643-5-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Jarkko Sakkinen Remove deprecated portions and document enum values. Signed-off-by: Jarkko Sakkinen Signed-off-by: James Bottomley --- include/linux/tpm.h | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/include/linux/tpm.h b/include/linux/tpm.h index bb0e8718a432..0a8c1351adc2 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -297,15 +297,14 @@ struct tpm_header { }; } __packed; -/* A string buffer type for constructing TPM commands. This is based on the - * ideas of string buffer code in security/keys/trusted.h but is heap based - * in order to keep the stack usage minimal. - */ - enum tpm_buf_flags { + /* the capacity exceeded: */ TPM_BUF_OVERFLOW = BIT(0), }; +/* + * A string buffer type for constructing TPM commands. + */ struct tpm_buf { unsigned int flags; u8 *data; From patchwork Mon Apr 29 20:27:54 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647676 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2BA5913AD2F; Mon, 29 Apr 2024 20:29:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422548; cv=none; b=JENpteRt2AzbcxapcMa6MYOI1XrwIPwVk/MoBcpTpgq58fO9AI2+4jUO11OfL/7mQ4azouCcFnAJAgua/+QZHycHtTQ5O9WpUfByqUJei0rxcoJwCbTzvM8HJAOw8DTYdXSoAl8qumVhie4yyLxXVefASMDc37foj/0g9Rrt9eU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422548; c=relaxed/simple; bh=6ks3bmvuYUE58vztBDISP6iQvbdzJBgPsZsoww3ykCU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=E0DtUeaUl9nbHz6eCEX2uL1Mfdu9KDv1NQOMa6JEYiYkVoNgLLNp22/eioW2a8zUZjNgeKJyelU55v79MuRgEgHqArErM6Ab/D9FihYVvlw9L3OwzZuzNy7RoliCvs61KXiDRmffn52JFJrZtU4vYIilx5qZ3OywzBbMmS3+P+8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=aP75Vg7b; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="aP75Vg7b" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422546; bh=6ks3bmvuYUE58vztBDISP6iQvbdzJBgPsZsoww3ykCU=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=aP75Vg7bQ7SUbM5ClZptOVhSq8GEawQUcI1eTYzugQtxCLlijAQMK1rR2yAlncIZc knlok5tspMfZXeQiZo+Xj9+nxdhCjyoSUOgJheGjcAeekRCvKw0Bi8q8TXGOoK2p0y gP9FkroufIQR0TFshyoCCdBUJNG0it/taaOnJgRk= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id A6EF51281D87; Mon, 29 Apr 2024 16:29:06 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id i3ave2BWqRub; Mon, 29 Apr 2024 16:29:06 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 17A2212819F3; Mon, 29 Apr 2024 16:29:06 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 05/22] tpm: Store the length of the tpm_buf data separately. Date: Mon, 29 Apr 2024 16:27:54 -0400 Message-Id: <20240429202811.13643-6-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Jarkko Sakkinen TPM2B buffers, or sized buffers, have a two byte header, which contains the length of the payload as a 16-bit big-endian number, without counting in the space taken by the header. This differs from encoding in the TPM header where the length includes also the bytes taken by the header. Unbound the length of a tpm_buf from the value stored to the TPM command header. A separate encoding and decoding step so that different buffer types can be supported, with variant header format and length encoding. Signed-off-by: Jarkko Sakkinen Signed-off-by: James Bottomley --- drivers/char/tpm/tpm-buf.c | 48 +++++++++++++++++------ drivers/char/tpm/tpm-interface.c | 1 + include/keys/trusted_tpm.h | 2 - include/linux/tpm.h | 6 +-- security/keys/trusted-keys/trusted_tpm1.c | 9 +++-- 5 files changed, 46 insertions(+), 20 deletions(-) diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c index 96cee41d5b9c..3f39893f3bb1 100644 --- a/drivers/char/tpm/tpm-buf.c +++ b/drivers/char/tpm/tpm-buf.c @@ -3,25 +3,44 @@ * Handling of TPM command and other buffers. */ +#include #include #include +/** + * tpm_buf_init() - Allocate and initialize a TPM command + * @buf: A &tpm_buf + * @tag: TPM_TAG_RQU_COMMAND, TPM2_ST_NO_SESSIONS or TPM2_ST_SESSIONS + * @ordinal: A command ordinal + * + * Return: 0 or -ENOMEM + */ int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal) { buf->data = (u8 *)__get_free_page(GFP_KERNEL); if (!buf->data) return -ENOMEM; - buf->flags = 0; tpm_buf_reset(buf, tag, ordinal); return 0; } EXPORT_SYMBOL_GPL(tpm_buf_init); +/** + * tpm_buf_reset() - Initialize a TPM command + * @buf: A &tpm_buf + * @tag: TPM_TAG_RQU_COMMAND, TPM2_ST_NO_SESSIONS or TPM2_ST_SESSIONS + * @ordinal: A command ordinal + */ void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal) { struct tpm_header *head = (struct tpm_header *)buf->data; + WARN_ON(tag != TPM_TAG_RQU_COMMAND && tag != TPM2_ST_NO_SESSIONS && + tag != TPM2_ST_SESSIONS && tag != 0); + + buf->flags = 0; + buf->length = sizeof(*head); head->tag = cpu_to_be16(tag); head->length = cpu_to_be32(sizeof(*head)); head->ordinal = cpu_to_be32(ordinal); @@ -34,33 +53,40 @@ void tpm_buf_destroy(struct tpm_buf *buf) } EXPORT_SYMBOL_GPL(tpm_buf_destroy); +/** + * tpm_buf_length() - Return the number of bytes consumed by the data + * + * Return: The number of bytes consumed by the buffer + */ u32 tpm_buf_length(struct tpm_buf *buf) { - struct tpm_header *head = (struct tpm_header *)buf->data; - - return be32_to_cpu(head->length); + return buf->length; } EXPORT_SYMBOL_GPL(tpm_buf_length); -void tpm_buf_append(struct tpm_buf *buf, - const unsigned char *new_data, - unsigned int new_len) +/** + * tpm_buf_append() - Append data to an initialized buffer + * @buf: A &tpm_buf + * @new_data: A data blob + * @new_length: Size of the appended data + */ +void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length) { struct tpm_header *head = (struct tpm_header *)buf->data; - u32 len = tpm_buf_length(buf); /* Return silently if overflow has already happened. */ if (buf->flags & TPM_BUF_OVERFLOW) return; - if ((len + new_len) > PAGE_SIZE) { + if ((buf->length + new_length) > PAGE_SIZE) { WARN(1, "tpm_buf: overflow\n"); buf->flags |= TPM_BUF_OVERFLOW; return; } - memcpy(&buf->data[len], new_data, new_len); - head->length = cpu_to_be32(len + new_len); + memcpy(&buf->data[buf->length], new_data, new_length); + buf->length += new_length; + head->length = cpu_to_be32(buf->length); } EXPORT_SYMBOL_GPL(tpm_buf_append); diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index f940045a014e..5da134f12c9a 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -232,6 +232,7 @@ ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf, if (len < min_rsp_body_length + TPM_HEADER_SIZE) return -EFAULT; + buf->length = len; return 0; } EXPORT_SYMBOL_GPL(tpm_transmit_cmd); diff --git a/include/keys/trusted_tpm.h b/include/keys/trusted_tpm.h index 7769b726863a..a088b33fd0e3 100644 --- a/include/keys/trusted_tpm.h +++ b/include/keys/trusted_tpm.h @@ -6,8 +6,6 @@ #include /* implementation specific TPM constants */ -#define MAX_BUF_SIZE 1024 -#define TPM_GETRANDOM_SIZE 14 #define TPM_SIZE_OFFSET 2 #define TPM_RETURN_OFFSET 6 #define TPM_DATA_OFFSET 10 diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 0a8c1351adc2..1d7b39b5c383 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -306,7 +306,8 @@ enum tpm_buf_flags { * A string buffer type for constructing TPM commands. */ struct tpm_buf { - unsigned int flags; + u32 flags; + u32 length; u8 *data; }; @@ -329,8 +330,7 @@ int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal); void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal); void tpm_buf_destroy(struct tpm_buf *buf); u32 tpm_buf_length(struct tpm_buf *buf); -void tpm_buf_append(struct tpm_buf *buf, const unsigned char *new_data, - unsigned int new_len); +void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length); void tpm_buf_append_u8(struct tpm_buf *buf, const u8 value); void tpm_buf_append_u16(struct tpm_buf *buf, const u16 value); void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value); diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c index 37bce84eef99..89c9798d1800 100644 --- a/security/keys/trusted-keys/trusted_tpm1.c +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -367,6 +367,7 @@ int trusted_tpm_send(unsigned char *cmd, size_t buflen) return rc; buf.flags = 0; + buf.length = buflen; buf.data = cmd; dump_tpm_buf(cmd); rc = tpm_transmit_cmd(chip, &buf, 4, "sending data"); @@ -417,7 +418,7 @@ static int osap(struct tpm_buf *tb, struct osapsess *s, tpm_buf_append_u32(tb, handle); tpm_buf_append(tb, ononce, TPM_NONCE_SIZE); - ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE); + ret = trusted_tpm_send(tb->data, tb->length); if (ret < 0) return ret; @@ -441,7 +442,7 @@ int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce) return -ENODEV; tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OIAP); - ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE); + ret = trusted_tpm_send(tb->data, tb->length); if (ret < 0) return ret; @@ -553,7 +554,7 @@ static int tpm_seal(struct tpm_buf *tb, uint16_t keytype, tpm_buf_append_u8(tb, cont); tpm_buf_append(tb, td->pubauth, SHA1_DIGEST_SIZE); - ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE); + ret = trusted_tpm_send(tb->data, tb->length); if (ret < 0) goto out; @@ -644,7 +645,7 @@ static int tpm_unseal(struct tpm_buf *tb, tpm_buf_append_u8(tb, cont); tpm_buf_append(tb, authdata2, SHA1_DIGEST_SIZE); - ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE); + ret = trusted_tpm_send(tb->data, tb->length); if (ret < 0) { pr_info("authhmac failed (%d)\n", ret); return ret; From patchwork Mon Apr 29 20:27:55 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647677 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1A88613AD2F; Mon, 29 Apr 2024 20:29:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422560; cv=none; b=f1aXZ8OkxBivJikpisc3AMCjMOV5w0d2GmpuvGxedCplD9DxYauje/XfBPAK3bCkNvvUavAWXXUuD7WNLwcoX3OwM3dviK2u3Fe+1dGvHsssyR1dQ1yr2TvtimXIwvtsUoNINl9HDVkpuH04VHJ8FG3J61Tm/+2KoXh+IDzQTuw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422560; c=relaxed/simple; bh=GhlA/Rq82/QUrouorinlF9Wm+3ULLc25ENkn8rx/tUg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=qUIRyD4xwwy18gu/GCgtfX88TiLs60VKswWiSvRBbf9m5ZxOtxf/OWBxKlnqSvG52iz2ZoHSYVCkx535LR5AGqIXrw6XbCVnvMgFsEWUUCA8alCMM4P3fI6qnFauJ35+5jMN5QgeyClLbtz+q61xQky6gRsifci9wO3Je1Q+pEA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=xZOLgkXw; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="xZOLgkXw" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422558; bh=GhlA/Rq82/QUrouorinlF9Wm+3ULLc25ENkn8rx/tUg=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=xZOLgkXwqhr4spcMDc5Tq1za5rFz1FV4fDdNYg+ijI7P9PtnlOgTjVvAuPJRq82mi OhcrTIOk09+mJ9ocxX+jb8laKZhvbk4d7obuBZcL6JlushSgyy6rhTJhsn1pMffQo5 llrXrakebjA8rcf8IIKzRQTNvH4ZIgEYcFDFqhQo= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 8CB541281D87; Mon, 29 Apr 2024 16:29:18 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id SHoqPGxA2FRk; Mon, 29 Apr 2024 16:29:18 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id F298D12819F3; Mon, 29 Apr 2024 16:29:17 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 06/22] tpm: TPM2B formatted buffers Date: Mon, 29 Apr 2024 16:27:55 -0400 Message-Id: <20240429202811.13643-7-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Jarkko Sakkinen Declare tpm_buf_init_sized() and tpm_buf_reset_sized() for creating TPM2B formatted buffers. These buffers are also known as sized buffers in the specifications and literature. Signed-off-by: Jarkko Sakkinen Signed-off-by: James Bottomley --- drivers/char/tpm/tpm-buf.c | 38 +++++++++++++++++++++++++++++++++++--- include/linux/tpm.h | 4 ++++ 2 files changed, 39 insertions(+), 3 deletions(-) diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c index 3f39893f3bb1..099b4a56c5d5 100644 --- a/drivers/char/tpm/tpm-buf.c +++ b/drivers/char/tpm/tpm-buf.c @@ -47,6 +47,36 @@ void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal) } EXPORT_SYMBOL_GPL(tpm_buf_reset); +/** + * tpm_buf_init_sized() - Allocate and initialize a sized (TPM2B) buffer + * @buf: A @tpm_buf + * + * Return: 0 or -ENOMEM + */ +int tpm_buf_init_sized(struct tpm_buf *buf) +{ + buf->data = (u8 *)__get_free_page(GFP_KERNEL); + if (!buf->data) + return -ENOMEM; + + tpm_buf_reset_sized(buf); + return 0; +} +EXPORT_SYMBOL_GPL(tpm_buf_init_sized); + +/** + * tpm_buf_reset_sized() - Initialize a sized buffer + * @buf: A &tpm_buf + */ +void tpm_buf_reset_sized(struct tpm_buf *buf) +{ + buf->flags = TPM_BUF_TPM2B; + buf->length = 2; + buf->data[0] = 0; + buf->data[1] = 0; +} +EXPORT_SYMBOL_GPL(tpm_buf_reset_sized); + void tpm_buf_destroy(struct tpm_buf *buf) { free_page((unsigned long)buf->data); @@ -72,8 +102,6 @@ EXPORT_SYMBOL_GPL(tpm_buf_length); */ void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length) { - struct tpm_header *head = (struct tpm_header *)buf->data; - /* Return silently if overflow has already happened. */ if (buf->flags & TPM_BUF_OVERFLOW) return; @@ -86,7 +114,11 @@ void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length) memcpy(&buf->data[buf->length], new_data, new_length); buf->length += new_length; - head->length = cpu_to_be32(buf->length); + + if (buf->flags & TPM_BUF_TPM2B) + ((__be16 *)buf->data)[0] = cpu_to_be16(buf->length - 2); + else + ((struct tpm_header *)buf->data)->length = cpu_to_be32(buf->length); } EXPORT_SYMBOL_GPL(tpm_buf_append); diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 1d7b39b5c383..715db4a91c1f 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -300,6 +300,8 @@ struct tpm_header { enum tpm_buf_flags { /* the capacity exceeded: */ TPM_BUF_OVERFLOW = BIT(0), + /* TPM2B format: */ + TPM_BUF_TPM2B = BIT(1), }; /* @@ -328,6 +330,8 @@ struct tpm2_hash { int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal); void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal); +int tpm_buf_init_sized(struct tpm_buf *buf); +void tpm_buf_reset_sized(struct tpm_buf *buf); void tpm_buf_destroy(struct tpm_buf *buf); u32 tpm_buf_length(struct tpm_buf *buf); void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length); From patchwork Mon Apr 29 20:27:56 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647678 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2121513AD2F; Mon, 29 Apr 2024 20:29:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422568; cv=none; b=F8NuLyJKUvQz979sFAFl0hqeyeSJz6AtFq8Y5jS/rOw7JXHEsN2OTBVzuJcWszIPJdAqojSOvSQNOMQDVfcuZ8oV/CF0u4kdRlMcDR2yM2CsBfALbYcj7Wyv7p0fQGNBT9esOBqsKHiSJcQKXyrVUEYdYWbCp2POtKm2Y5UHjK0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422568; c=relaxed/simple; bh=B5x/0D2Tjpcday6Z/hf7mIF1khP/vscYwie2pM+QlM8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=INdTCsDGqJJZlCuIKEd3GFngDqNJvLBw3/ozYkGDFv6NktJxLVJ6waCyp8mYggV/uBG1QqrF3TzbogElGp1KSUKGDwFM0MzMzzEcbC9zKZyvvkQQw7C4DCJibLlZr2y0t42Gx7xcs62hIPUbLtyOP3axSTc9dBK2gzwVbf3t4CI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=uC8bZVLv; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="uC8bZVLv" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422566; bh=B5x/0D2Tjpcday6Z/hf7mIF1khP/vscYwie2pM+QlM8=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=uC8bZVLvP8CNiSUaAJgXVXozQ6mqpSL/0kToU8p5l4TH6W1Hy0U+NC1W6wr4BwtAq ZpGREatIFg9BeIAwaLqP7EzsqcptfVn+N4VbEdNlRjPI7TJVGjImO/wB2kJ3bxkfTJ vKzxhIIF2uftbdgaqLgAvkSDTM3YfXpBJfqydbs4= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 896951281ED0; Mon, 29 Apr 2024 16:29:26 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id f9b2yf6ydlhb; Mon, 29 Apr 2024 16:29:26 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id D11391281D87; Mon, 29 Apr 2024 16:29:25 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 07/22] tpm: Add tpm_buf_read_{u8,u16,u32} Date: Mon, 29 Apr 2024 16:27:56 -0400 Message-Id: <20240429202811.13643-8-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Jarkko Sakkinen Declare reader functions for the instances of struct tpm_buf. If the read goes out of boundary, TPM_BUF_BOUNDARY_ERROR is set, and subsequent read will do nothing. Signed-off-by: Jarkko Sakkinen Signed-off-by: James Bottomley --- drivers/char/tpm/tpm-buf.c | 79 +++++++++++++++++++++++++++++++++++++- include/linux/tpm.h | 5 +++ 2 files changed, 83 insertions(+), 1 deletion(-) diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c index 099b4a56c5d5..32619e9ab4fa 100644 --- a/drivers/char/tpm/tpm-buf.c +++ b/drivers/char/tpm/tpm-buf.c @@ -107,7 +107,7 @@ void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length) return; if ((buf->length + new_length) > PAGE_SIZE) { - WARN(1, "tpm_buf: overflow\n"); + WARN(1, "tpm_buf: write overflow\n"); buf->flags |= TPM_BUF_OVERFLOW; return; } @@ -143,3 +143,80 @@ void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value) tpm_buf_append(buf, (u8 *)&value2, 4); } EXPORT_SYMBOL_GPL(tpm_buf_append_u32); + +/** + * tpm_buf_read() - Read from a TPM buffer + * @buf: &tpm_buf instance + * @offset: offset within the buffer + * @count: the number of bytes to read + * @output: the output buffer + */ +static void tpm_buf_read(struct tpm_buf *buf, off_t *offset, size_t count, void *output) +{ + off_t next_offset; + + /* Return silently if overflow has already happened. */ + if (buf->flags & TPM_BUF_BOUNDARY_ERROR) + return; + + next_offset = *offset + count; + if (next_offset > buf->length) { + WARN(1, "tpm_buf: read out of boundary\n"); + buf->flags |= TPM_BUF_BOUNDARY_ERROR; + return; + } + + memcpy(output, &buf->data[*offset], count); + *offset = next_offset; +} + +/** + * tpm_buf_read_u8() - Read 8-bit word from a TPM buffer + * @buf: &tpm_buf instance + * @offset: offset within the buffer + * + * Return: next 8-bit word + */ +u8 tpm_buf_read_u8(struct tpm_buf *buf, off_t *offset) +{ + u8 value; + + tpm_buf_read(buf, offset, sizeof(value), &value); + + return value; +} +EXPORT_SYMBOL_GPL(tpm_buf_read_u8); + +/** + * tpm_buf_read_u16() - Read 16-bit word from a TPM buffer + * @buf: &tpm_buf instance + * @offset: offset within the buffer + * + * Return: next 16-bit word + */ +u16 tpm_buf_read_u16(struct tpm_buf *buf, off_t *offset) +{ + u16 value; + + tpm_buf_read(buf, offset, sizeof(value), &value); + + return be16_to_cpu(value); +} +EXPORT_SYMBOL_GPL(tpm_buf_read_u16); + +/** + * tpm_buf_read_u32() - Read 32-bit word from a TPM buffer + * @buf: &tpm_buf instance + * @offset: offset within the buffer + * + * Return: next 32-bit word + */ +u32 tpm_buf_read_u32(struct tpm_buf *buf, off_t *offset) +{ + u32 value; + + tpm_buf_read(buf, offset, sizeof(value), &value); + + return be32_to_cpu(value); +} +EXPORT_SYMBOL_GPL(tpm_buf_read_u32); diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 715db4a91c1f..e8172f81c562 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -302,6 +302,8 @@ enum tpm_buf_flags { TPM_BUF_OVERFLOW = BIT(0), /* TPM2B format: */ TPM_BUF_TPM2B = BIT(1), + /* read out of boundary: */ + TPM_BUF_BOUNDARY_ERROR = BIT(2), }; /* @@ -338,6 +340,9 @@ void tpm_buf_append(struct tpm_buf *buf, const u8 *new_data, u16 new_length); void tpm_buf_append_u8(struct tpm_buf *buf, const u8 value); void tpm_buf_append_u16(struct tpm_buf *buf, const u16 value); void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value); +u8 tpm_buf_read_u8(struct tpm_buf *buf, off_t *offset); +u16 tpm_buf_read_u16(struct tpm_buf *buf, off_t *offset); +u32 tpm_buf_read_u32(struct tpm_buf *buf, off_t *offset); /* * Check if TPM device is in the firmware upgrade mode. From patchwork Mon Apr 29 20:27:57 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647679 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 567281420A8; Mon, 29 Apr 2024 20:29:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422576; cv=none; b=b+BPQ0Uhzd+EPemVKoLWp+OH6Njg9jVlIzjFhKLJKee9EoBEZCmgxipnVHz2awsp4O9bNdwY81oKyvYWehk+SYz6EZ+6cc8GPUPP5cLwksatmRvMJmyDOQydIuTNtH4WyTHVie/aK5ed89++oDie/mPOI2H4+fPhqALiGMgzR/k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422576; c=relaxed/simple; bh=pXRdPrv2/iSHR8+AavcpYIBVOA6deo1c3pS+IW1A248=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=seiV/u6VbHg+roz/GgJ3ydP86hcX/kq9Rvi6V1iZ/YOsQdCn+0yA5YMXQrKeWJTIijcEHkdSl8ejfdRj4ABaa1M9YT2u1XeE3xi8rrEf2OascUg2YbbC6J/ZdP9Q2YyHOPhGsK5Jlumd3gpZsH+QCW6KXSdnwZX4bVD229YE0QY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=q2aogp1d; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="q2aogp1d" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422574; bh=pXRdPrv2/iSHR8+AavcpYIBVOA6deo1c3pS+IW1A248=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=q2aogp1dB5gK9iXCAPhwz+vm0wFpjWrorGzBn701IoXHAAFCh4Kn0UmmDN9zNF7wz T8G8juk2T+czi5iwbjh5Pa0CCYdfdoM61nl/KqmV1rnPmbwfqm6u7SgDpyPND4Hh2L v/xpzJ1e3xsrylCjLecgowNLglzaPPDg7EGNHAuU= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id B1CA112819F3; Mon, 29 Apr 2024 16:29:34 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id TKGfumsqGNnn; Mon, 29 Apr 2024 16:29:34 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 26A1D1281D87; Mon, 29 Apr 2024 16:29:34 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 08/22] KEYS: trusted: tpm2: Use struct tpm_buf for sized buffers Date: Mon, 29 Apr 2024 16:27:57 -0400 Message-Id: <20240429202811.13643-9-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Jarkko Sakkinen Take advantage of the new sized buffer (TPM2B) mode of struct tpm_buf in tpm2_seal_trusted(). This allows to add robustness to the command construction without requiring to calculate buffer sizes manually. Signed-off-by: Jarkko Sakkinen Signed-off-by: James Bottomley --- security/keys/trusted-keys/trusted_tpm2.c | 54 +++++++++++++---------- 1 file changed, 31 insertions(+), 23 deletions(-) diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c index bc700f85f80b..97b1dfca2dba 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -228,8 +228,9 @@ int tpm2_seal_trusted(struct tpm_chip *chip, struct trusted_key_payload *payload, struct trusted_key_options *options) { + off_t offset = TPM_HEADER_SIZE; + struct tpm_buf buf, sized; int blob_len = 0; - struct tpm_buf buf; u32 hash; u32 flags; int i; @@ -258,6 +259,14 @@ int tpm2_seal_trusted(struct tpm_chip *chip, return rc; } + rc = tpm_buf_init_sized(&sized); + if (rc) { + tpm_buf_destroy(&buf); + tpm_put_ops(chip); + return rc; + } + + tpm_buf_reset(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE); tpm_buf_append_u32(&buf, options->keyhandle); tpm2_buf_append_auth(&buf, TPM2_RS_PW, NULL /* nonce */, 0, @@ -266,36 +275,36 @@ int tpm2_seal_trusted(struct tpm_chip *chip, TPM_DIGEST_SIZE); /* sensitive */ - tpm_buf_append_u16(&buf, 4 + options->blobauth_len + payload->key_len); + tpm_buf_append_u16(&sized, options->blobauth_len); - tpm_buf_append_u16(&buf, options->blobauth_len); if (options->blobauth_len) - tpm_buf_append(&buf, options->blobauth, options->blobauth_len); + tpm_buf_append(&sized, options->blobauth, options->blobauth_len); - tpm_buf_append_u16(&buf, payload->key_len); - tpm_buf_append(&buf, payload->key, payload->key_len); + tpm_buf_append_u16(&sized, payload->key_len); + tpm_buf_append(&sized, payload->key, payload->key_len); + tpm_buf_append(&buf, sized.data, sized.length); /* public */ - tpm_buf_append_u16(&buf, 14 + options->policydigest_len); - tpm_buf_append_u16(&buf, TPM_ALG_KEYEDHASH); - tpm_buf_append_u16(&buf, hash); + tpm_buf_reset_sized(&sized); + tpm_buf_append_u16(&sized, TPM_ALG_KEYEDHASH); + tpm_buf_append_u16(&sized, hash); /* key properties */ flags = 0; flags |= options->policydigest_len ? 0 : TPM2_OA_USER_WITH_AUTH; - flags |= payload->migratable ? 0 : (TPM2_OA_FIXED_TPM | - TPM2_OA_FIXED_PARENT); - tpm_buf_append_u32(&buf, flags); + flags |= payload->migratable ? 0 : (TPM2_OA_FIXED_TPM | TPM2_OA_FIXED_PARENT); + tpm_buf_append_u32(&sized, flags); /* policy */ - tpm_buf_append_u16(&buf, options->policydigest_len); + tpm_buf_append_u16(&sized, options->policydigest_len); if (options->policydigest_len) - tpm_buf_append(&buf, options->policydigest, - options->policydigest_len); + tpm_buf_append(&sized, options->policydigest, options->policydigest_len); /* public parameters */ - tpm_buf_append_u16(&buf, TPM_ALG_NULL); - tpm_buf_append_u16(&buf, 0); + tpm_buf_append_u16(&sized, TPM_ALG_NULL); + tpm_buf_append_u16(&sized, 0); + + tpm_buf_append(&buf, sized.data, sized.length); /* outside info */ tpm_buf_append_u16(&buf, 0); @@ -312,21 +321,20 @@ int tpm2_seal_trusted(struct tpm_chip *chip, if (rc) goto out; - blob_len = be32_to_cpup((__be32 *) &buf.data[TPM_HEADER_SIZE]); - if (blob_len > MAX_BLOB_SIZE) { + blob_len = tpm_buf_read_u32(&buf, &offset); + if (blob_len > MAX_BLOB_SIZE || buf.flags & TPM_BUF_BOUNDARY_ERROR) { rc = -E2BIG; goto out; } - if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 4 + blob_len) { + if (buf.length - offset < blob_len) { rc = -EFAULT; goto out; } - blob_len = tpm2_key_encode(payload, options, - &buf.data[TPM_HEADER_SIZE + 4], - blob_len); + blob_len = tpm2_key_encode(payload, options, &buf.data[offset], blob_len); out: + tpm_buf_destroy(&sized); tpm_buf_destroy(&buf); if (rc > 0) { From patchwork Mon Apr 29 20:27:58 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647680 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A8D771419A2; Mon, 29 Apr 2024 20:29:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422585; cv=none; b=X1FvxsOMyJoV4PIgGuttRTfasxVIKtSFEQLaHLHLwvFuYNd6nRiLhZWJdIsG9ESgVUoi6coXCujbVp3YKFNTowbcypJviDTPELLtuHxM14fgY/fGu27hPVR/r/VoAHBke9pTWagEO01ors6OirZevkj5s+HLJH1/ziNym2uHb9E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422585; c=relaxed/simple; bh=2EyJcM1e+1jD78Prh/afYQp787QkhVigSeeUVI7CuOk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=qzEp+VqB3l/xyaN2oMBg92jqlYeJpUuZrqYnKHUIN6N3i0S5NMAKr9P76DZc5aL2OdXJ5Av/vCxBMaS3ikE+/N1v5N71r/kl2ht+XlP95tn0VLlguiI1kRCPZJEmlPOC2IjvD6ooS5Qr381KKm/ARpWe+kkR6R+qlb/NEv0UqDM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=VRh7N1qh; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="VRh7N1qh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422583; bh=2EyJcM1e+1jD78Prh/afYQp787QkhVigSeeUVI7CuOk=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=VRh7N1qhA64Ng+5TlZfOVRFjmVs9yr6/0CQPxvBZRr0Tx79ZDCWNYJ4+SY0ffFI4Y KHwckqkYbsokty9XppDR5+649OEzxooSdNwgzHLNlrQhfWZC/U6wjiq2C7r5iH9QOg 7UUEZ62qY8TwDcbtmjV5UT8AjE0deMy61vuTdsNg= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 537A41281ED0; Mon, 29 Apr 2024 16:29:43 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id emtcsdW0GWa8; Mon, 29 Apr 2024 16:29:43 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id B59ED12819F3; Mon, 29 Apr 2024 16:29:42 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 09/22] crypto: lib - implement library version of AES in CFB mode Date: Mon, 29 Apr 2024 16:27:58 -0400 Message-Id: <20240429202811.13643-10-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Ard Biesheuvel Implement AES in CFB mode using the existing, mostly constant-time generic AES library implementation. This will be used by the TPM code to encrypt communications with TPM hardware, which is often a discrete component connected using sniffable wires or traces. While a CFB template does exist, using a skcipher is a major pain for non-performance critical synchronous crypto where the algorithm is known at compile time and the data is in contiguous buffers with valid kernel virtual addresses. Tested-by: James Bottomley Reviewed-by: James Bottomley Reviewed-by: Jarkko Sakkinen Link: https://lore.kernel.org/all/20230216201410.15010-1-James.Bottomley@HansenPartnership.com/ Signed-off-by: Ard Biesheuvel Signed-off-by: James Bottomley --- include/crypto/aes.h | 5 + lib/crypto/Kconfig | 5 + lib/crypto/Makefile | 3 + lib/crypto/aescfb.c | 257 +++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 270 insertions(+) create mode 100644 lib/crypto/aescfb.c diff --git a/include/crypto/aes.h b/include/crypto/aes.h index 2090729701ab..9339da7c20a8 100644 --- a/include/crypto/aes.h +++ b/include/crypto/aes.h @@ -87,4 +87,9 @@ void aes_decrypt(const struct crypto_aes_ctx *ctx, u8 *out, const u8 *in); extern const u8 crypto_aes_sbox[]; extern const u8 crypto_aes_inv_sbox[]; +void aescfb_encrypt(const struct crypto_aes_ctx *ctx, u8 *dst, const u8 *src, + int len, const u8 iv[AES_BLOCK_SIZE]); +void aescfb_decrypt(const struct crypto_aes_ctx *ctx, u8 *dst, const u8 *src, + int len, const u8 iv[AES_BLOCK_SIZE]); + #endif diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig index 45436bfc6dff..b01253cac70a 100644 --- a/lib/crypto/Kconfig +++ b/lib/crypto/Kconfig @@ -8,6 +8,11 @@ config CRYPTO_LIB_UTILS config CRYPTO_LIB_AES tristate +config CRYPTO_LIB_AESCFB + tristate + select CRYPTO_LIB_AES + select CRYPTO_LIB_UTILS + config CRYPTO_LIB_AESGCM tristate select CRYPTO_LIB_AES diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile index 8d1446c2be71..969baab8c805 100644 --- a/lib/crypto/Makefile +++ b/lib/crypto/Makefile @@ -10,6 +10,9 @@ obj-$(CONFIG_CRYPTO_LIB_CHACHA_GENERIC) += libchacha.o obj-$(CONFIG_CRYPTO_LIB_AES) += libaes.o libaes-y := aes.o +obj-$(CONFIG_CRYPTO_LIB_AESCFB) += libaescfb.o +libaescfb-y := aescfb.o + obj-$(CONFIG_CRYPTO_LIB_AESGCM) += libaesgcm.o libaesgcm-y := aesgcm.o diff --git a/lib/crypto/aescfb.c b/lib/crypto/aescfb.c new file mode 100644 index 000000000000..749dc1258a44 --- /dev/null +++ b/lib/crypto/aescfb.c @@ -0,0 +1,257 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Minimal library implementation of AES in CFB mode + * + * Copyright 2023 Google LLC + */ + +#include + +#include +#include + +#include + +static void aescfb_encrypt_block(const struct crypto_aes_ctx *ctx, void *dst, + const void *src) +{ + unsigned long flags; + + /* + * In AES-CFB, the AES encryption operates on known 'plaintext' (the IV + * and ciphertext), making it susceptible to timing attacks on the + * encryption key. The AES library already mitigates this risk to some + * extent by pulling the entire S-box into the caches before doing any + * substitutions, but this strategy is more effective when running with + * interrupts disabled. + */ + local_irq_save(flags); + aes_encrypt(ctx, dst, src); + local_irq_restore(flags); +} + +/** + * aescfb_encrypt - Perform AES-CFB encryption on a block of data + * + * @ctx: The AES-CFB key schedule + * @dst: Pointer to the ciphertext output buffer + * @src: Pointer the plaintext (may equal @dst for encryption in place) + * @len: The size in bytes of the plaintext and ciphertext. + * @iv: The initialization vector (IV) to use for this block of data + */ +void aescfb_encrypt(const struct crypto_aes_ctx *ctx, u8 *dst, const u8 *src, + int len, const u8 iv[AES_BLOCK_SIZE]) +{ + u8 ks[AES_BLOCK_SIZE]; + const u8 *v = iv; + + while (len > 0) { + aescfb_encrypt_block(ctx, ks, v); + crypto_xor_cpy(dst, src, ks, min(len, AES_BLOCK_SIZE)); + v = dst; + + dst += AES_BLOCK_SIZE; + src += AES_BLOCK_SIZE; + len -= AES_BLOCK_SIZE; + } + + memzero_explicit(ks, sizeof(ks)); +} +EXPORT_SYMBOL(aescfb_encrypt); + +/** + * aescfb_decrypt - Perform AES-CFB decryption on a block of data + * + * @ctx: The AES-CFB key schedule + * @dst: Pointer to the plaintext output buffer + * @src: Pointer the ciphertext (may equal @dst for decryption in place) + * @len: The size in bytes of the plaintext and ciphertext. + * @iv: The initialization vector (IV) to use for this block of data + */ +void aescfb_decrypt(const struct crypto_aes_ctx *ctx, u8 *dst, const u8 *src, + int len, const u8 iv[AES_BLOCK_SIZE]) +{ + u8 ks[2][AES_BLOCK_SIZE]; + + aescfb_encrypt_block(ctx, ks[0], iv); + + for (int i = 0; len > 0; i ^= 1) { + if (len > AES_BLOCK_SIZE) + /* + * Generate the keystream for the next block before + * performing the XOR, as that may update in place and + * overwrite the ciphertext. + */ + aescfb_encrypt_block(ctx, ks[!i], src); + + crypto_xor_cpy(dst, src, ks[i], min(len, AES_BLOCK_SIZE)); + + dst += AES_BLOCK_SIZE; + src += AES_BLOCK_SIZE; + len -= AES_BLOCK_SIZE; + } + + memzero_explicit(ks, sizeof(ks)); +} +EXPORT_SYMBOL(aescfb_decrypt); + +MODULE_DESCRIPTION("Generic AES-CFB library"); +MODULE_AUTHOR("Ard Biesheuvel "); +MODULE_LICENSE("GPL"); + +#ifndef CONFIG_CRYPTO_MANAGER_DISABLE_TESTS + +/* + * Test code below. Vectors taken from crypto/testmgr.h + */ + +static struct { + u8 ptext[64]; + u8 ctext[64]; + + u8 key[AES_MAX_KEY_SIZE]; + u8 iv[AES_BLOCK_SIZE]; + + int klen; + int len; +} const aescfb_tv[] __initconst = { + { /* From NIST SP800-38A */ + .key = "\x2b\x7e\x15\x16\x28\xae\xd2\xa6" + "\xab\xf7\x15\x88\x09\xcf\x4f\x3c", + .klen = 16, + .iv = "\x00\x01\x02\x03\x04\x05\x06\x07" + "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f", + .ptext = "\x6b\xc1\xbe\xe2\x2e\x40\x9f\x96" + "\xe9\x3d\x7e\x11\x73\x93\x17\x2a" + "\xae\x2d\x8a\x57\x1e\x03\xac\x9c" + "\x9e\xb7\x6f\xac\x45\xaf\x8e\x51" + "\x30\xc8\x1c\x46\xa3\x5c\xe4\x11" + "\xe5\xfb\xc1\x19\x1a\x0a\x52\xef" + "\xf6\x9f\x24\x45\xdf\x4f\x9b\x17" + "\xad\x2b\x41\x7b\xe6\x6c\x37\x10", + .ctext = "\x3b\x3f\xd9\x2e\xb7\x2d\xad\x20" + "\x33\x34\x49\xf8\xe8\x3c\xfb\x4a" + "\xc8\xa6\x45\x37\xa0\xb3\xa9\x3f" + "\xcd\xe3\xcd\xad\x9f\x1c\xe5\x8b" + "\x26\x75\x1f\x67\xa3\xcb\xb1\x40" + "\xb1\x80\x8c\xf1\x87\xa4\xf4\xdf" + "\xc0\x4b\x05\x35\x7c\x5d\x1c\x0e" + "\xea\xc4\xc6\x6f\x9f\xf7\xf2\xe6", + .len = 64, + }, { + .key = "\x8e\x73\xb0\xf7\xda\x0e\x64\x52" + "\xc8\x10\xf3\x2b\x80\x90\x79\xe5" + "\x62\xf8\xea\xd2\x52\x2c\x6b\x7b", + .klen = 24, + .iv = "\x00\x01\x02\x03\x04\x05\x06\x07" + "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f", + .ptext = "\x6b\xc1\xbe\xe2\x2e\x40\x9f\x96" + "\xe9\x3d\x7e\x11\x73\x93\x17\x2a" + "\xae\x2d\x8a\x57\x1e\x03\xac\x9c" + "\x9e\xb7\x6f\xac\x45\xaf\x8e\x51" + "\x30\xc8\x1c\x46\xa3\x5c\xe4\x11" + "\xe5\xfb\xc1\x19\x1a\x0a\x52\xef" + "\xf6\x9f\x24\x45\xdf\x4f\x9b\x17" + "\xad\x2b\x41\x7b\xe6\x6c\x37\x10", + .ctext = "\xcd\xc8\x0d\x6f\xdd\xf1\x8c\xab" + "\x34\xc2\x59\x09\xc9\x9a\x41\x74" + "\x67\xce\x7f\x7f\x81\x17\x36\x21" + "\x96\x1a\x2b\x70\x17\x1d\x3d\x7a" + "\x2e\x1e\x8a\x1d\xd5\x9b\x88\xb1" + "\xc8\xe6\x0f\xed\x1e\xfa\xc4\xc9" + "\xc0\x5f\x9f\x9c\xa9\x83\x4f\xa0" + "\x42\xae\x8f\xba\x58\x4b\x09\xff", + .len = 64, + }, { + .key = "\x60\x3d\xeb\x10\x15\xca\x71\xbe" + "\x2b\x73\xae\xf0\x85\x7d\x77\x81" + "\x1f\x35\x2c\x07\x3b\x61\x08\xd7" + "\x2d\x98\x10\xa3\x09\x14\xdf\xf4", + .klen = 32, + .iv = "\x00\x01\x02\x03\x04\x05\x06\x07" + "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f", + .ptext = "\x6b\xc1\xbe\xe2\x2e\x40\x9f\x96" + "\xe9\x3d\x7e\x11\x73\x93\x17\x2a" + "\xae\x2d\x8a\x57\x1e\x03\xac\x9c" + "\x9e\xb7\x6f\xac\x45\xaf\x8e\x51" + "\x30\xc8\x1c\x46\xa3\x5c\xe4\x11" + "\xe5\xfb\xc1\x19\x1a\x0a\x52\xef" + "\xf6\x9f\x24\x45\xdf\x4f\x9b\x17" + "\xad\x2b\x41\x7b\xe6\x6c\x37\x10", + .ctext = "\xdc\x7e\x84\xbf\xda\x79\x16\x4b" + "\x7e\xcd\x84\x86\x98\x5d\x38\x60" + "\x39\xff\xed\x14\x3b\x28\xb1\xc8" + "\x32\x11\x3c\x63\x31\xe5\x40\x7b" + "\xdf\x10\x13\x24\x15\xe5\x4b\x92" + "\xa1\x3e\xd0\xa8\x26\x7a\xe2\xf9" + "\x75\xa3\x85\x74\x1a\xb9\xce\xf8" + "\x20\x31\x62\x3d\x55\xb1\xe4\x71", + .len = 64, + }, { /* > 16 bytes, not a multiple of 16 bytes */ + .key = "\x2b\x7e\x15\x16\x28\xae\xd2\xa6" + "\xab\xf7\x15\x88\x09\xcf\x4f\x3c", + .klen = 16, + .iv = "\x00\x01\x02\x03\x04\x05\x06\x07" + "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f", + .ptext = "\x6b\xc1\xbe\xe2\x2e\x40\x9f\x96" + "\xe9\x3d\x7e\x11\x73\x93\x17\x2a" + "\xae", + .ctext = "\x3b\x3f\xd9\x2e\xb7\x2d\xad\x20" + "\x33\x34\x49\xf8\xe8\x3c\xfb\x4a" + "\xc8", + .len = 17, + }, { /* < 16 bytes */ + .key = "\x2b\x7e\x15\x16\x28\xae\xd2\xa6" + "\xab\xf7\x15\x88\x09\xcf\x4f\x3c", + .klen = 16, + .iv = "\x00\x01\x02\x03\x04\x05\x06\x07" + "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f", + .ptext = "\x6b\xc1\xbe\xe2\x2e\x40\x9f", + .ctext = "\x3b\x3f\xd9\x2e\xb7\x2d\xad", + .len = 7, + }, +}; + +static int __init libaescfb_init(void) +{ + for (int i = 0; i < ARRAY_SIZE(aescfb_tv); i++) { + struct crypto_aes_ctx ctx; + u8 buf[64]; + + if (aes_expandkey(&ctx, aescfb_tv[i].key, aescfb_tv[i].klen)) { + pr_err("aes_expandkey() failed on vector %d\n", i); + return -ENODEV; + } + + aescfb_encrypt(&ctx, buf, aescfb_tv[i].ptext, aescfb_tv[i].len, + aescfb_tv[i].iv); + if (memcmp(buf, aescfb_tv[i].ctext, aescfb_tv[i].len)) { + pr_err("aescfb_encrypt() #1 failed on vector %d\n", i); + return -ENODEV; + } + + /* decrypt in place */ + aescfb_decrypt(&ctx, buf, buf, aescfb_tv[i].len, aescfb_tv[i].iv); + if (memcmp(buf, aescfb_tv[i].ptext, aescfb_tv[i].len)) { + pr_err("aescfb_decrypt() failed on vector %d\n", i); + return -ENODEV; + } + + /* encrypt in place */ + aescfb_encrypt(&ctx, buf, buf, aescfb_tv[i].len, aescfb_tv[i].iv); + if (memcmp(buf, aescfb_tv[i].ctext, aescfb_tv[i].len)) { + pr_err("aescfb_encrypt() #2 failed on vector %d\n", i); + + return -ENODEV; + } + + } + return 0; +} +module_init(libaescfb_init); + +static void __exit libaescfb_exit(void) +{ +} +module_exit(libaescfb_exit); +#endif From patchwork Mon Apr 29 20:27:59 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647681 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B3C3A13AD2F; Mon, 29 Apr 2024 20:29:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422595; cv=none; b=aDRE5vjcNdcisN/EAXKYxR7Ws+Z6r1DTF1xOnDSrwtbQ+zcUHqwtc81iPseI9sRwki1Y382K0OAFGtqpISjpuyqPFR80Yjrcj7IWW4Y7I9Fc6OzHo+clxZ5H+LK/HmAdxMc2d9IJkIxJc4zGLSC9qlNTnGEKBustVonKkICv6Kk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422595; c=relaxed/simple; bh=jf2OFp9fwM5S2/gUWTtBTD0TYENRgGwBW8qxb+2VC5s=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=lqyZLVlklKOmfcsbtCnUU9BW26ROLUCoHY1WrXDLH8PfLTZuUoPXlX/DNBLvD8+XSjqeyPvYj8gfGniNQKxxnfiqkwj5N+u414thTH962kOi94J3lPMPSoml+lnK9EhutMei4a/USijhKL7L9MWmrx0ADBYNehvf/m3WBAlvnhU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=loNJ4PaO; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="loNJ4PaO" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422594; bh=jf2OFp9fwM5S2/gUWTtBTD0TYENRgGwBW8qxb+2VC5s=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=loNJ4PaOt1PAxDOWPIDXz4HSufXYMUzULR5vNCjlwLb8aZAU1CL4jCbTvk55mlGpH zcjCTUbXi/7Zv2PiDfTSC+rLPXQacjHqxLECM0pc9OVsB1LJpYAXX2dmwmFwj2AhnS MlpL4QptZSyvXw52o/gK9UvVdpZqM9XeDAAhzsw0= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 6095A12819F3; Mon, 29 Apr 2024 16:29:54 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id ohXtigUrJt2x; Mon, 29 Apr 2024 16:29:54 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id CAA3B1281D87; Mon, 29 Apr 2024 16:29:53 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 10/22] tpm: add buffer function to point to returned parameters Date: Mon, 29 Apr 2024 16:27:59 -0400 Message-Id: <20240429202811.13643-11-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Replace all instances of &buf.data[TPM_HEADER_SIZE] with a new function tpm_buf_parameters() because encryption sessions change where the return parameters are located in the buffer since if a return session is present they're 4 bytes beyond the header with those 4 bytes giving the parameter length. If there is no return session, then they're in the usual place immediately after the header. Signed-off-by: James Bottomley Reviewed-by: Stefan Berger Reviewed-by: Jarkko Sakkinen --- v4: add kdoc v5: update kdoc add review v7: add review --- drivers/char/tpm/tpm-buf.c | 28 ++++++++++++++++++++++++++++ include/linux/tpm.h | 2 ++ 2 files changed, 30 insertions(+) diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c index 32619e9ab4fa..bb81180495d1 100644 --- a/drivers/char/tpm/tpm-buf.c +++ b/drivers/char/tpm/tpm-buf.c @@ -220,3 +220,31 @@ u32 tpm_buf_read_u32(struct tpm_buf *buf, off_t *offset) return be32_to_cpu(value); } EXPORT_SYMBOL_GPL(tpm_buf_read_u32); + +static u16 tpm_buf_tag(struct tpm_buf *buf) +{ + struct tpm_header *head = (struct tpm_header *)buf->data; + + return be16_to_cpu(head->tag); +} + +/** + * tpm_buf_parameters - return the TPM response parameters area of the tpm_buf + * @buf: tpm_buf to use + * + * Where the parameters are located depends on the tag of a TPM + * command (it's immediately after the header for TPM_ST_NO_SESSIONS + * or 4 bytes after for TPM_ST_SESSIONS). Evaluate this and return a + * pointer to the first byte of the parameters area. + * + * @return: pointer to parameters area + */ +u8 *tpm_buf_parameters(struct tpm_buf *buf) +{ + int offset = TPM_HEADER_SIZE; + + if (tpm_buf_tag(buf) == TPM2_ST_SESSIONS) + offset += 4; + + return &buf->data[offset]; +} diff --git a/include/linux/tpm.h b/include/linux/tpm.h index e8172f81c562..6be263509e81 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -344,6 +344,8 @@ u8 tpm_buf_read_u8(struct tpm_buf *buf, off_t *offset); u16 tpm_buf_read_u16(struct tpm_buf *buf, off_t *offset); u32 tpm_buf_read_u32(struct tpm_buf *buf, off_t *offset); +u8 *tpm_buf_parameters(struct tpm_buf *buf); + /* * Check if TPM device is in the firmware upgrade mode. */ From patchwork Mon Apr 29 20:28:00 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647682 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7A4451419BC; Mon, 29 Apr 2024 20:30:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422605; cv=none; b=XYgmRs0qJliQR0u7VisL2Htv4vGJIfGR1NuEvxfdRFAqCYmloW2Tt85ghAxX77NhVDyiuAp3EIvWooiQ4GzYD9UZlPByoVBOLCPi0dahK8cInLKnjQ6/tv4GPbtkF97VUQC0hJODzbmlBPb3SZholkWV/f//+MPDj0F4DKh3jF4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422605; c=relaxed/simple; bh=dwuGyYQKq/rRnuhCGin2sg2u+8jXwR0vnt4cki80AZQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=tz7NpnYZj2Vd0S38+TkDkJdZdSE6+Loc2paG4JnQu6MzQMHG8rVXBW15YCLP0dnYFlkXNwCTfc62ZmwOAO3v4MV7iL4VB4Ejn9PUOUCCtwcFawMNscyVNNhGEwiSa9i52nZRo2KYi7s3ep1n4ga1ijFf2wEXF4RH34nb4FlUzos= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=VGeQupP6; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="VGeQupP6" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422603; bh=dwuGyYQKq/rRnuhCGin2sg2u+8jXwR0vnt4cki80AZQ=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=VGeQupP6RB4w4devzU/6yGvTR9etLH0TOorSXXoxlsDc4R5RfWGjsCLS54fo1Ekbz sHuMwzW+o1KIVQ670y3CRt/3Oo5W2xQknkQND8x4ivDZWbapbH+YDyheO+Tq8bMG11 gIRkudA3geu2kGx7fagVRssUl7ZqXL6xYdfnCL/s= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id EF4B81281D87; Mon, 29 Apr 2024 16:30:03 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id bxvgKmpFozg1; Mon, 29 Apr 2024 16:30:03 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 61FD712819F3; Mon, 29 Apr 2024 16:30:03 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 11/22] tpm: export the context save and load commands Date: Mon, 29 Apr 2024 16:28:00 -0400 Message-Id: <20240429202811.13643-12-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The TPM2 session HMAC and encryption handling code needs to save and restore a single volatile context for the elliptic curve version of the NULL seed, so export the APIs which do this for internal use. Signed-off-by: James Bottomley Reviewed-by: Stefan Berger Reviewed-by: Jarkko Sakkinen --- v5: add review v7: add review --- drivers/char/tpm/tpm.h | 4 ++++ drivers/char/tpm/tpm2-space.c | 8 ++++---- 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 61445f1dc46d..cbc9d1e2974d 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -312,6 +312,10 @@ int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space, void *buf, size_t *bufsiz); int tpm_devs_add(struct tpm_chip *chip); void tpm_devs_remove(struct tpm_chip *chip); +int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf, + unsigned int buf_size, unsigned int *offset); +int tpm2_load_context(struct tpm_chip *chip, u8 *buf, + unsigned int *offset, u32 *handle); void tpm_bios_log_setup(struct tpm_chip *chip); void tpm_bios_log_teardown(struct tpm_chip *chip); diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c index 363afdd4d1d3..24479a81c23c 100644 --- a/drivers/char/tpm/tpm2-space.c +++ b/drivers/char/tpm/tpm2-space.c @@ -68,8 +68,8 @@ void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space) kfree(space->session_buf); } -static int tpm2_load_context(struct tpm_chip *chip, u8 *buf, - unsigned int *offset, u32 *handle) +int tpm2_load_context(struct tpm_chip *chip, u8 *buf, + unsigned int *offset, u32 *handle) { struct tpm_buf tbuf; struct tpm2_context *ctx; @@ -119,8 +119,8 @@ static int tpm2_load_context(struct tpm_chip *chip, u8 *buf, return 0; } -static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf, - unsigned int buf_size, unsigned int *offset) +int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf, + unsigned int buf_size, unsigned int *offset) { struct tpm_buf tbuf; unsigned int body_size; From patchwork Mon Apr 29 20:28:01 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647683 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 691811448DE; Mon, 29 Apr 2024 20:30:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422616; cv=none; b=O49fP99GE8JLU65OkSVhDS4zYPyioxNlrBPQo7rUVzzk6uNNDJmSd0gcNj2jpoyVB2wckJEtLpgVmhxix/qknFQpU8JtFGYUtybkOmfFqWE9EA6PL9uEjqS19xMQkFPVxdbhbDcLJcLWefxv+WRxFc7G64CAOMRnhQM3ZOsXSNg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422616; c=relaxed/simple; bh=Tqj+wHY4SJbdG+f4IQ9yXxIvPgzOhPik5ZVRl7SH0qo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=fc8uUIRmslhAAk4wPNWYmHI/yihgtnEzjOevss3vbWGQSg4VgXdrUm7HK0kFzkw8ttQZa8nzoEJZ7W9e4Xxsb+lsDFVM2MonhnGyTOuCYhEZFV7h7zmYyvS7EkcBd8Pt0jFQE5q6FyRTTF0UTaYplZFle5I8x8rehlv+tJWekuk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=gCgqEp4U; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="gCgqEp4U" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422613; bh=Tqj+wHY4SJbdG+f4IQ9yXxIvPgzOhPik5ZVRl7SH0qo=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=gCgqEp4UZDdQN4lGrNPGmLDIqjhRBFX0ZxYhyuZj7sUwXA6OnY/h9CI2GdcDB5f+c UIzkhaASKgxzrn43rp73tWb0ghweRC91zWAPxhasKOu6LURtt06AFvqa2RgLkySy/e m10/ILSPjO9aUFiRYAexsM8vakNyWMn4iyiQt80Q= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 97A851281D87; Mon, 29 Apr 2024 16:30:13 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id TAE3FcuEg-gp; Mon, 29 Apr 2024 16:30:13 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id ABEBD12819F3; Mon, 29 Apr 2024 16:30:12 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 12/22] tpm: Add NULL primary creation Date: Mon, 29 Apr 2024 16:28:01 -0400 Message-Id: <20240429202811.13643-13-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The session handling code uses a "salted" session, meaning a session whose salt is encrypted to the public part of another TPM key so an observer cannot obtain it (and thus deduce the session keys). This patch creates and context saves in the tpm_chip area the primary key of the NULL hierarchy for this purpose. Signed-off-by: James Bottomley Reviewed-by: Jarkko Sakkinen --- v6: split out of original HMAC patch update config name v7: rename null seed parameters v8: format changes and move template to tpm.h --- drivers/char/tpm/Kconfig | 11 ++ drivers/char/tpm/Makefile | 1 + drivers/char/tpm/tpm.h | 10 + drivers/char/tpm/tpm2-cmd.c | 5 + drivers/char/tpm/tpm2-sessions.c | 316 +++++++++++++++++++++++++++++++ include/linux/tpm.h | 69 +++++++ 6 files changed, 412 insertions(+) create mode 100644 drivers/char/tpm/tpm2-sessions.c diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig index 927088b2c3d3..ab16d347579f 100644 --- a/drivers/char/tpm/Kconfig +++ b/drivers/char/tpm/Kconfig @@ -27,6 +27,17 @@ menuconfig TCG_TPM if TCG_TPM +config TCG_TPM2_HMAC + bool "Use HMAC and encrypted transactions on the TPM bus" + default y + help + Setting this causes us to deploy a scheme which uses request + and response HMACs in addition to encryption for + communicating with the TPM to prevent or detect bus snooping + and interposer attacks (see tpm-security.rst). Saying Y + here adds some encryption overhead to all kernel to TPM + transactions. + config HW_RANDOM_TPM bool "TPM HW Random Number Generator support" depends on TCG_TPM && HW_RANDOM && !(TCG_TPM=y && HW_RANDOM=m) diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile index ad3594e383e1..4c695b0388f3 100644 --- a/drivers/char/tpm/Makefile +++ b/drivers/char/tpm/Makefile @@ -17,6 +17,7 @@ tpm-y += eventlog/tpm1.o tpm-y += eventlog/tpm2.o tpm-y += tpm-buf.o +tpm-$(CONFIG_TCG_TPM2_HMAC) += tpm2-sessions.o tpm-$(CONFIG_ACPI) += tpm_ppi.o eventlog/acpi.o tpm-$(CONFIG_EFI) += eventlog/efi.o tpm-$(CONFIG_OF) += eventlog/of.o diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index cbc9d1e2974d..6b8b9956ba69 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -321,4 +321,14 @@ void tpm_bios_log_setup(struct tpm_chip *chip); void tpm_bios_log_teardown(struct tpm_chip *chip); int tpm_dev_common_init(void); void tpm_dev_common_exit(void); + +#ifdef CONFIG_TCG_TPM2_HMAC +int tpm2_sessions_init(struct tpm_chip *chip); +#else +static inline int tpm2_sessions_init(struct tpm_chip *chip) +{ + return 0; +} +#endif + #endif diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index 93545be190a5..b0e72fb563d9 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -759,6 +759,11 @@ int tpm2_auto_startup(struct tpm_chip *chip) rc = 0; } + if (rc) + goto out; + + rc = tpm2_sessions_init(chip); + out: /* * Infineon TPM in field upgrade mode will return no data for the number diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c new file mode 100644 index 000000000000..fc3f032df467 --- /dev/null +++ b/drivers/char/tpm/tpm2-sessions.c @@ -0,0 +1,316 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright (C) 2018 James.Bottomley@HansenPartnership.com + * + */ + +#include "tpm.h" +#include + +/** + * tpm2_parse_create_primary() - parse the data returned from TPM_CC_CREATE_PRIMARY + * + * @chip: The TPM the primary was created under + * @buf: The response buffer from the chip + * @handle: pointer to be filled in with the return handle of the primary + * @hierarchy: The hierarchy the primary was created for + * + * @returns: 0 on success or a positive TPM or negative standard error + */ +static int tpm2_parse_create_primary(struct tpm_chip *chip, struct tpm_buf *buf, + u32 *handle, u32 hierarchy) +{ + struct tpm_header *head = (struct tpm_header *)buf->data; + off_t offset_r = TPM_HEADER_SIZE, offset_t; + u16 len = TPM_HEADER_SIZE; + u32 total_len = be32_to_cpu(head->length); + u32 val, param_len; + + *handle = tpm_buf_read_u32(buf, &offset_r); + param_len = tpm_buf_read_u32(buf, &offset_r); + /* + * param_len doesn't include the header, but all the other + * lengths and offsets do, so add it to parm len to make + * the comparisons easier + */ + param_len += TPM_HEADER_SIZE; + + if (param_len + 8 > total_len) + return -EINVAL; + len = tpm_buf_read_u16(buf, &offset_r); + offset_t = offset_r; + /* now we have the public area, compute the name of the object */ + put_unaligned_be16(TPM_ALG_SHA256, chip->null_key_name); + sha256(&buf->data[offset_r], len, chip->null_key_name + 2); + + /* validate the public key */ + val = tpm_buf_read_u16(buf, &offset_t); + + /* key type (must be what we asked for) */ + if (val != TPM_ALG_ECC) + return -EINVAL; + val = tpm_buf_read_u16(buf, &offset_t); + + /* name algorithm */ + if (val != TPM_ALG_SHA256) + return -EINVAL; + val = tpm_buf_read_u32(buf, &offset_t); + + /* object properties */ + if (val != TPM2_OA_TMPL) + return -EINVAL; + + /* auth policy (empty) */ + val = tpm_buf_read_u16(buf, &offset_t); + if (val != 0) + return -EINVAL; + + /* symmetric key parameters */ + val = tpm_buf_read_u16(buf, &offset_t); + if (val != TPM_ALG_AES) + return -EINVAL; + + /* symmetric key length */ + val = tpm_buf_read_u16(buf, &offset_t); + if (val != AES_KEY_BITS) + return -EINVAL; + + /* symmetric encryption scheme */ + val = tpm_buf_read_u16(buf, &offset_t); + if (val != TPM_ALG_CFB) + return -EINVAL; + + /* signing scheme */ + val = tpm_buf_read_u16(buf, &offset_t); + if (val != TPM_ALG_NULL) + return -EINVAL; + + /* ECC Curve */ + val = tpm_buf_read_u16(buf, &offset_t); + if (val != TPM2_ECC_NIST_P256) + return -EINVAL; + + /* KDF Scheme */ + val = tpm_buf_read_u16(buf, &offset_t); + if (val != TPM_ALG_NULL) + return -EINVAL; + + /* extract public key (x and y points) */ + val = tpm_buf_read_u16(buf, &offset_t); + if (val != EC_PT_SZ) + return -EINVAL; + memcpy(chip->null_ec_key_x, &buf->data[offset_t], val); + offset_t += val; + val = tpm_buf_read_u16(buf, &offset_t); + if (val != EC_PT_SZ) + return -EINVAL; + memcpy(chip->null_ec_key_y, &buf->data[offset_t], val); + offset_t += val; + + /* original length of the whole TPM2B */ + offset_r += len; + + /* should have exactly consumed the TPM2B public structure */ + if (offset_t != offset_r) + return -EINVAL; + if (offset_r > param_len) + return -EINVAL; + + /* creation data (skip) */ + len = tpm_buf_read_u16(buf, &offset_r); + offset_r += len; + if (offset_r > param_len) + return -EINVAL; + + /* creation digest (must be sha256) */ + len = tpm_buf_read_u16(buf, &offset_r); + offset_r += len; + if (len != SHA256_DIGEST_SIZE || offset_r > param_len) + return -EINVAL; + + /* TPMT_TK_CREATION follows */ + /* tag, must be TPM_ST_CREATION (0x8021) */ + val = tpm_buf_read_u16(buf, &offset_r); + if (val != TPM2_ST_CREATION || offset_r > param_len) + return -EINVAL; + + /* hierarchy */ + val = tpm_buf_read_u32(buf, &offset_r); + if (val != hierarchy || offset_r > param_len) + return -EINVAL; + + /* the ticket digest HMAC (might not be sha256) */ + len = tpm_buf_read_u16(buf, &offset_r); + offset_r += len; + if (offset_r > param_len) + return -EINVAL; + + /* + * finally we have the name, which is a sha256 digest plus a 2 + * byte algorithm type + */ + len = tpm_buf_read_u16(buf, &offset_r); + if (offset_r + len != param_len + 8) + return -EINVAL; + if (len != SHA256_DIGEST_SIZE + 2) + return -EINVAL; + + if (memcmp(chip->null_key_name, &buf->data[offset_r], + SHA256_DIGEST_SIZE + 2) != 0) { + dev_err(&chip->dev, "NULL Seed name comparison failed\n"); + return -EINVAL; + } + + return 0; +} + +/** + * tpm2_create_primary() - create a primary key using a fixed P-256 template + * + * @chip: the TPM chip to create under + * @hierarchy: The hierarchy handle to create under + * @handle: The returned volatile handle on success + * + * For platforms that might not have a persistent primary, this can be + * used to create one quickly on the fly (it uses Elliptic Curve not + * RSA, so even slow TPMs can create one fast). The template uses the + * TCG mandated H one for non-endorsement ECC primaries, i.e. P-256 + * elliptic curve (the only current one all TPM2s are required to + * have) a sha256 name hash and no policy. + * + * @returns: 0 on success or positive TPM or negative error. + */ +static int tpm2_create_primary(struct tpm_chip *chip, u32 hierarchy, + u32 *handle) +{ + int rc; + struct tpm_buf buf; + struct tpm_buf template; + + rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE_PRIMARY); + if (rc) + return rc; + + rc = tpm_buf_init_sized(&template); + if (rc) { + tpm_buf_destroy(&buf); + return rc; + } + + /* + * create the template. Note: in order for userspace to + * verify the security of the system, it will have to create + * and certify this NULL primary, meaning all the template + * parameters will have to be identical, so conform exactly to + * the TCG TPM v2.0 Provisioning Guidance for the SRK ECC + * key H template (H has zero size unique points) + */ + + /* key type */ + tpm_buf_append_u16(&template, TPM_ALG_ECC); + + /* name algorithm */ + tpm_buf_append_u16(&template, TPM_ALG_SHA256); + + /* object properties */ + tpm_buf_append_u32(&template, TPM2_OA_TMPL); + + /* sauth policy (empty) */ + tpm_buf_append_u16(&template, 0); + + /* BEGIN parameters: key specific; for ECC*/ + + /* symmetric algorithm */ + tpm_buf_append_u16(&template, TPM_ALG_AES); + + /* bits for symmetric algorithm */ + tpm_buf_append_u16(&template, AES_KEY_BITS); + + /* algorithm mode (must be CFB) */ + tpm_buf_append_u16(&template, TPM_ALG_CFB); + + /* scheme (NULL means any scheme) */ + tpm_buf_append_u16(&template, TPM_ALG_NULL); + + /* ECC Curve ID */ + tpm_buf_append_u16(&template, TPM2_ECC_NIST_P256); + + /* KDF Scheme */ + tpm_buf_append_u16(&template, TPM_ALG_NULL); + + /* unique: key specific; for ECC it is two zero size points */ + tpm_buf_append_u16(&template, 0); + tpm_buf_append_u16(&template, 0); + + /* END parameters */ + + /* primary handle */ + tpm_buf_append_u32(&buf, hierarchy); + tpm_buf_append_empty_auth(&buf, TPM2_RS_PW); + + /* sensitive create size is 4 for two empty buffers */ + tpm_buf_append_u16(&buf, 4); + + /* sensitive create auth data (empty) */ + tpm_buf_append_u16(&buf, 0); + + /* sensitive create sensitive data (empty) */ + tpm_buf_append_u16(&buf, 0); + + /* the public template */ + tpm_buf_append(&buf, template.data, template.length); + tpm_buf_destroy(&template); + + /* outside info (empty) */ + tpm_buf_append_u16(&buf, 0); + + /* creation PCR (none) */ + tpm_buf_append_u32(&buf, 0); + + rc = tpm_transmit_cmd(chip, &buf, 0, + "attempting to create NULL primary"); + + if (rc == TPM2_RC_SUCCESS) + rc = tpm2_parse_create_primary(chip, &buf, handle, hierarchy); + + tpm_buf_destroy(&buf); + + return rc; +} + +static int tpm2_create_null_primary(struct tpm_chip *chip) +{ + u32 null_key; + int rc; + + rc = tpm2_create_primary(chip, TPM2_RH_NULL, &null_key); + + if (rc == TPM2_RC_SUCCESS) { + unsigned int offset = 0; /* dummy offset for null key context */ + + rc = tpm2_save_context(chip, null_key, chip->null_key_context, + sizeof(chip->null_key_context), &offset); + tpm2_flush_context(chip, null_key); + } + + return rc; +} + +/** + * tpm2_sessions_init() - start of day initialization for the sessions code + * @chip: TPM chip + * + * Derive and context save the null primary and allocate memory in the + * struct tpm_chip for the authorizations. + */ +int tpm2_sessions_init(struct tpm_chip *chip) +{ + int rc; + + rc = tpm2_create_null_primary(chip); + if (rc) + dev_err(&chip->dev, "TPM: security failed (NULL seed derivation): %d\n", rc); + + return rc; +} diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 6be263509e81..bc8c9a350e23 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -23,6 +23,7 @@ #include #include #include +#include #define TPM_DIGEST_SIZE 20 /* Max TPM v1.2 PCR size */ #define TPM_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE @@ -35,12 +36,15 @@ struct trusted_key_options; enum tpm_algorithms { TPM_ALG_ERROR = 0x0000, TPM_ALG_SHA1 = 0x0004, + TPM_ALG_AES = 0x0006, TPM_ALG_KEYEDHASH = 0x0008, TPM_ALG_SHA256 = 0x000B, TPM_ALG_SHA384 = 0x000C, TPM_ALG_SHA512 = 0x000D, TPM_ALG_NULL = 0x0010, TPM_ALG_SM3_256 = 0x0012, + TPM_ALG_ECC = 0x0023, + TPM_ALG_CFB = 0x0043, }; /* @@ -49,6 +53,11 @@ enum tpm_algorithms { */ #define TPM_MAX_HASHES 5 +enum tpm2_curves { + TPM2_ECC_NONE = 0x0000, + TPM2_ECC_NIST_P256 = 0x0003, +}; + struct tpm_digest { u16 alg_id; u8 digest[TPM_MAX_DIGEST_SIZE]; @@ -116,6 +125,20 @@ struct tpm_chip_seqops { const struct seq_operations *seqops; }; +/* fixed define for the curve we use which is NIST_P256 */ +#define EC_PT_SZ 32 + +/* + * fixed define for the size of a name. This is actually HASHALG size + * plus 2, so 32 for SHA256 + */ +#define TPM2_NAME_SIZE 34 + +/* + * The maximum size for an object context + */ +#define TPM2_MAX_CONTEXT_SIZE 4096 + struct tpm_chip { struct device dev; struct device devs; @@ -170,6 +193,17 @@ struct tpm_chip { /* active locality */ int locality; + +#ifdef CONFIG_TCG_TPM2_HMAC + /* details for communication security via sessions */ + + /* saved context for NULL seed */ + u8 null_key_context[TPM2_MAX_CONTEXT_SIZE]; + /* name of NULL seed */ + u8 null_key_name[TPM2_NAME_SIZE]; + u8 null_ec_key_x[EC_PT_SZ]; + u8 null_ec_key_y[EC_PT_SZ]; +#endif }; #define TPM_HEADER_SIZE 10 @@ -194,6 +228,7 @@ enum tpm2_timeouts { enum tpm2_structures { TPM2_ST_NO_SESSIONS = 0x8001, TPM2_ST_SESSIONS = 0x8002, + TPM2_ST_CREATION = 0x8021, }; /* Indicates from what layer of the software stack the error comes from */ @@ -243,6 +278,7 @@ enum tpm2_command_codes { }; enum tpm2_permanent_handles { + TPM2_RH_NULL = 0x40000007, TPM2_RS_PW = 0x40000009, }; @@ -318,9 +354,28 @@ struct tpm_buf { enum tpm2_object_attributes { TPM2_OA_FIXED_TPM = BIT(1), TPM2_OA_FIXED_PARENT = BIT(4), + TPM2_OA_SENSITIVE_DATA_ORIGIN = BIT(5), TPM2_OA_USER_WITH_AUTH = BIT(6), + TPM2_OA_NO_DA = BIT(10), + TPM2_OA_RESTRICTED = BIT(16), + TPM2_OA_DECRYPT = BIT(17), }; +/* + * definitions for the canonical template. These are mandated + * by the TCG key template documents + */ + +#define AES_KEY_BYTES AES_KEYSIZE_128 +#define AES_KEY_BITS (AES_KEY_BYTES*8) +#define TPM2_OA_TMPL (TPM2_OA_NO_DA | \ + TPM2_OA_FIXED_TPM | \ + TPM2_OA_FIXED_PARENT | \ + TPM2_OA_SENSITIVE_DATA_ORIGIN | \ + TPM2_OA_USER_WITH_AUTH | \ + TPM2_OA_DECRYPT | \ + TPM2_OA_RESTRICTED) + enum tpm2_session_attributes { TPM2_SA_CONTINUE_SESSION = BIT(0), }; @@ -373,6 +428,16 @@ extern int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, extern int tpm_get_random(struct tpm_chip *chip, u8 *data, size_t max); extern struct tpm_chip *tpm_default_chip(void); void tpm2_flush_context(struct tpm_chip *chip, u32 handle); + +static inline void tpm_buf_append_empty_auth(struct tpm_buf *buf, u32 handle) +{ + /* simple authorization for empty auth */ + tpm_buf_append_u32(buf, 9); /* total length of auth */ + tpm_buf_append_u32(buf, handle); + tpm_buf_append_u16(buf, 0); /* nonce len */ + tpm_buf_append_u8(buf, 0); /* attributes */ + tpm_buf_append_u16(buf, 0); /* hmac len */ +} #else static inline int tpm_is_tpm2(struct tpm_chip *chip) { @@ -399,5 +464,9 @@ static inline struct tpm_chip *tpm_default_chip(void) { return NULL; } + +static inline void tpm_buf_append_empty_auth(struct tpm_buf *buf, u32 handle) +{ +} #endif #endif From patchwork Mon Apr 29 20:28:02 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647684 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7A292205E20; Mon, 29 Apr 2024 20:30:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422623; cv=none; b=n4lM6G9lt+JL6YysyVbB0KvrD63MY0gME///J1RMgEHklCF6gR+/WcEQYZsXO9W7De/NmWwSpdpqN14a6HE4oLwH+KpMBIXj6txJp6JktArcPeI/xUCn+n1LK7X09WD0pIyfcC53HeGdGs/E4ykt3tq1JqoFtdH6rNvWiy0PeT0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422623; c=relaxed/simple; bh=ADbyj/D4/GRL6pC11KrRKdy77pnDq0Ht/S916BJH0OY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=rcVYAbXXFZvK7LRXElE6frcFEHUakCPx5FOYgVxuxwi1jZ9xEMzajGCHQGJRnKsxMbO/HjUJ7T5Qn0rO8mqHwiPdIDtjf4Tm2LFK9cAEXXjL+VBlt0eezIKZ+HUeI22V2r20aKTK5d6GdaEXD2qMcDxWqk5dj8WnIQwrc14X4a0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=VOMAL8u0; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="VOMAL8u0" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422621; bh=ADbyj/D4/GRL6pC11KrRKdy77pnDq0Ht/S916BJH0OY=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=VOMAL8u0Z24UNX95UxT1OBioGkyORt8puovdhIT2zO1B+N6zpb/9TS1TqoOrL673o QZ3Q6e5SUautgdKDIHgTaE9MToUiTS5RRd1mY+9nmXjGFAg2RNoyrBfiVlN42OhGTK t08kkkKmY+R3AbET2xCl5UOF8BBDvR6zjU3zviIQ= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id E639B1281D87; Mon, 29 Apr 2024 16:30:21 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id O4A1gon0sOp1; Mon, 29 Apr 2024 16:30:21 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 52F3412819F3; Mon, 29 Apr 2024 16:30:21 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 13/22] tpm: Add TCG mandated Key Derivation Functions (KDFs) Date: Mon, 29 Apr 2024 16:28:02 -0400 Message-Id: <20240429202811.13643-14-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The TCG mandates two Key derivation functions called KDFa and KDFe used to derive keys from seeds and elliptic curve points respectively. The definitions for these functions are found in the TPM 2.0 Library Specification Part 1 - Architecture Guide https://trustedcomputinggroup.org/resource/tpm-library-specification/ Implement a cut down version of each of these functions sufficient to support the key derivation needs of HMAC sessions. Signed-off-by: James Bottomley Reviewed-by: Jarkko Sakkinen --- v8: Add new patch containing KDFs --- drivers/char/tpm/Kconfig | 1 + drivers/char/tpm/tpm2-sessions.c | 105 +++++++++++++++++++++++++++++++ 2 files changed, 106 insertions(+) diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig index ab16d347579f..4873e6eae255 100644 --- a/drivers/char/tpm/Kconfig +++ b/drivers/char/tpm/Kconfig @@ -30,6 +30,7 @@ if TCG_TPM config TCG_TPM2_HMAC bool "Use HMAC and encrypted transactions on the TPM bus" default y + select CRYPTO_LIB_SHA256 help Setting this causes us to deploy a scheme which uses request and response HMACs in addition to encryption for diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c index fc3f032df467..8429e596f1eb 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -7,6 +7,111 @@ #include "tpm.h" #include +#include +#include + +/* + * It turns out the crypto hmac(sha256) is hard for us to consume + * because it assumes a fixed key and the TPM seems to change the key + * on every operation, so we weld the hmac init and final functions in + * here to give it the same usage characteristics as a regular hash + */ +static void tpm2_hmac_init(struct sha256_state *sctx, u8 *key, u32 key_len) +{ + u8 pad[SHA256_BLOCK_SIZE]; + int i; + + sha256_init(sctx); + for (i = 0; i < sizeof(pad); i++) { + if (i < key_len) + pad[i] = key[i]; + else + pad[i] = 0; + pad[i] ^= HMAC_IPAD_VALUE; + } + sha256_update(sctx, pad, sizeof(pad)); +} + +static void tpm2_hmac_final(struct sha256_state *sctx, u8 *key, u32 key_len, + u8 *out) +{ + u8 pad[SHA256_BLOCK_SIZE]; + int i; + + for (i = 0; i < sizeof(pad); i++) { + if (i < key_len) + pad[i] = key[i]; + else + pad[i] = 0; + pad[i] ^= HMAC_OPAD_VALUE; + } + + /* collect the final hash; use out as temporary storage */ + sha256_final(sctx, out); + + sha256_init(sctx); + sha256_update(sctx, pad, sizeof(pad)); + sha256_update(sctx, out, SHA256_DIGEST_SIZE); + sha256_final(sctx, out); +} + +/* + * assume hash sha256 and nonces u, v of size SHA256_DIGEST_SIZE but + * otherwise standard tpm2_KDFa. Note output is in bytes not bits. + */ +static void tpm2_KDFa(u8 *key, u32 key_len, const char *label, u8 *u, + u8 *v, u32 bytes, u8 *out) +{ + u32 counter = 1; + const __be32 bits = cpu_to_be32(bytes * 8); + + while (bytes > 0) { + struct sha256_state sctx; + __be32 c = cpu_to_be32(counter); + + tpm2_hmac_init(&sctx, key, key_len); + sha256_update(&sctx, (u8 *)&c, sizeof(c)); + sha256_update(&sctx, label, strlen(label)+1); + sha256_update(&sctx, u, SHA256_DIGEST_SIZE); + sha256_update(&sctx, v, SHA256_DIGEST_SIZE); + sha256_update(&sctx, (u8 *)&bits, sizeof(bits)); + tpm2_hmac_final(&sctx, key, key_len, out); + + bytes -= SHA256_DIGEST_SIZE; + counter++; + out += SHA256_DIGEST_SIZE; + } +} + +/* + * Somewhat of a bastardization of the real KDFe. We're assuming + * we're working with known point sizes for the input parameters and + * the hash algorithm is fixed at sha256. Because we know that the + * point size is 32 bytes like the hash size, there's no need to loop + * in this KDF. + */ +static void tpm2_KDFe(u8 z[EC_PT_SZ], const char *str, u8 *pt_u, u8 *pt_v, + u8 *out) +{ + struct sha256_state sctx; + /* + * this should be an iterative counter, but because we know + * we're only taking 32 bytes for the point using a sha256 + * hash which is also 32 bytes, there's only one loop + */ + __be32 c = cpu_to_be32(1); + + sha256_init(&sctx); + /* counter (BE) */ + sha256_update(&sctx, (u8 *)&c, sizeof(c)); + /* secret value */ + sha256_update(&sctx, z, EC_PT_SZ); + /* string including trailing zero */ + sha256_update(&sctx, str, strlen(str)+1); + sha256_update(&sctx, pt_u, EC_PT_SZ); + sha256_update(&sctx, pt_v, EC_PT_SZ); + sha256_final(&sctx, out); +} /** * tpm2_parse_create_primary() - parse the data returned from TPM_CC_CREATE_PRIMARY From patchwork Mon Apr 29 20:28:03 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647685 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9E6CF1494AC; Mon, 29 Apr 2024 20:30:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422630; cv=none; b=gHhOgJ/IncQ87sKpDekWUz92YqMbgjfAhvof84YbT5obVMC9xklJkx7/lO3ws4nmfWb190lrHi4eesA7cyZUcGaO+3oY4TudIMd8rrOpmbISH/aZsH48EjRxRpj+9qQebdpjhWTIq+rZNMw/GgvVbGklyKu/tSfrZefM9Vy4jnQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422630; c=relaxed/simple; bh=7Br4KUlC/K1af3Ebe3alPz1s00LgIabr8DP8GanWK/o=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=unuBerfYdic7nJNoq4piYwzD8ky1djfzKylajMJcbgd9Mub9LbOUIV8bAnYPu/jhs4tC0dWF6Jugi+yYLdAFdYuLsHvIiakgwFLp44bRmrO1fDe9dR4gYv1gbOh0qA5HzjI/FB1Ao6zFp2ndx/6f8NZwBNaHaRHTw9R97XNGI0I= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=kBbQXsQG; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="kBbQXsQG" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422627; bh=7Br4KUlC/K1af3Ebe3alPz1s00LgIabr8DP8GanWK/o=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=kBbQXsQG+ZJBluEg9ApqFTUWm6ZSI5dTOxPYFyLohgGQESmwGc/cq20i9f5wnY8Zn PhBw9W4JLvm7iJTWLcwtcx0w6nLcrzxbm34vl3ggc8a17j0JhuVGdgZrrDdpF+DiX2 NsUESYr5GhADCdfmVRuRSStCevbMW34Ci3KK7MBQ= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id F13F41281D87; Mon, 29 Apr 2024 16:30:27 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id oQ1eMhdsYFSU; Mon, 29 Apr 2024 16:30:27 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 548F812819F3; Mon, 29 Apr 2024 16:30:27 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 14/22] tpm: Add HMAC session start and end functions Date: Mon, 29 Apr 2024 16:28:03 -0400 Message-Id: <20240429202811.13643-15-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Add session based HMAC authentication plus parameter decryption and response encryption using AES. The basic design is to segregate all the nasty crypto, hash and hmac code into tpm2-sessions.c and export a usable API. The API first of all starts off by gaining a session with tpm2_start_auth_session() which initiates a session with the TPM and allocates an opaque tpm2_auth structure to handle the session parameters. The design is that session use will be single threaded from start to finish under the ops lock, so the tpm2_auth structure is stored in struct tpm2_chip to simpify the externally visible API. The session can be ended with tpm2_end_auth_session() which is designed only to be used in error legs. Ordinarily the further session API (future patches) will end or continue the session appropriately without having to call this. Signed-off-by: James Bottomley Reviewed-by: Ard Biesheuvel # crypto API parts Reviewed-by: Jarkko Sakkinen --- v6: split into new patch, update config variable v7: add tpm2_ prefix and memzero_explicit v8: cosmetic changes, split out KDFe and KDFa --- drivers/char/tpm/Kconfig | 2 + drivers/char/tpm/tpm-buf.c | 1 + drivers/char/tpm/tpm-chip.c | 3 + drivers/char/tpm/tpm2-sessions.c | 285 +++++++++++++++++++++++++++++++ include/linux/tpm.h | 34 ++++ 5 files changed, 325 insertions(+) diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig index 4873e6eae255..cecf617c9c90 100644 --- a/drivers/char/tpm/Kconfig +++ b/drivers/char/tpm/Kconfig @@ -30,6 +30,8 @@ if TCG_TPM config TCG_TPM2_HMAC bool "Use HMAC and encrypted transactions on the TPM bus" default y + select CRYPTO_ECDH + select CRYPTO_LIB_AESCFB select CRYPTO_LIB_SHA256 help Setting this causes us to deploy a scheme which uses request diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c index bb81180495d1..274130398569 100644 --- a/drivers/char/tpm/tpm-buf.c +++ b/drivers/char/tpm/tpm-buf.c @@ -44,6 +44,7 @@ void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal) head->tag = cpu_to_be16(tag); head->length = cpu_to_be32(sizeof(*head)); head->ordinal = cpu_to_be32(ordinal); + buf->handles = 0; } EXPORT_SYMBOL_GPL(tpm_buf_reset); diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 42b1062e33cd..d93937326b2e 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -275,6 +275,9 @@ static void tpm_dev_release(struct device *dev) kfree(chip->work_space.context_buf); kfree(chip->work_space.session_buf); kfree(chip->allocated_banks); +#ifdef CONFIG_TCG_TPM2_HMAC + kfree(chip->auth); +#endif kfree(chip); } diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c index 8429e596f1eb..71b3c0e75760 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -3,13 +3,101 @@ /* * Copyright (C) 2018 James.Bottomley@HansenPartnership.com * + * Cryptographic helper routines for handling TPM2 sessions for + * authorization HMAC and request response encryption. + * + * The idea is to ensure that every TPM command is HMAC protected by a + * session, meaning in-flight tampering would be detected and in + * addition all sensitive inputs and responses should be encrypted. + * + * The basic way this works is to use a TPM feature called salted + * sessions where a random secret used in session construction is + * encrypted to the public part of a known TPM key. The problem is we + * have no known keys, so initially a primary Elliptic Curve key is + * derived from the NULL seed (we use EC because most TPMs generate + * these keys much faster than RSA ones). The curve used is NIST_P256 + * because that's now mandated to be present in 'TCG TPM v2.0 + * Provisioning Guidance' + * + * Threat problems: the initial TPM2_CreatePrimary is not (and cannot + * be) session protected, so a clever Man in the Middle could return a + * public key they control to this command and from there intercept + * and decode all subsequent session based transactions. The kernel + * cannot mitigate this threat but, after boot, userspace can get + * proof this has not happened by asking the TPM to certify the NULL + * key. This certification would chain back to the TPM Endorsement + * Certificate and prove the NULL seed primary had not been tampered + * with and thus all sessions must have been cryptographically secure. + * To assist with this, the initial NULL seed public key name is made + * available in a sysfs file. + * + * Use of these functions: + * + * The design is all the crypto, hash and hmac gunk is confined in this + * file and never needs to be seen even by the kernel internal user. To + * the user there's an init function tpm2_sessions_init() that needs to + * be called once per TPM which generates the NULL seed primary key. + * + * These are the usage functions: + * + * tpm2_start_auth_session() which allocates the opaque auth structure + * and gets a session from the TPM. This must be called before + * any of the following functions. The session is protected by a + * session_key which is derived from a random salt value + * encrypted to the NULL seed. + * tpm2_end_auth_session() kills the session and frees the resources. + * Under normal operation this function is done by + * tpm_buf_check_hmac_response(), so this is only to be used on + * error legs where the latter is not executed. */ #include "tpm.h" +#include +#include #include +#include +#include #include #include +/* + * This is the structure that carries all the auth information (like + * session handle, nonces, session key and auth) from use to use it is + * designed to be opaque to anything outside. + */ +struct tpm2_auth { + u32 handle; + /* + * This has two meanings: before tpm_buf_fill_hmac_session() + * it marks the offset in the buffer of the start of the + * sessions (i.e. after all the handles). Once the buffer has + * been filled it markes the session number of our auth + * session so we can find it again in the response buffer. + * + * The two cases are distinguished because the first offset + * must always be greater than TPM_HEADER_SIZE and the second + * must be less than or equal to 5. + */ + u32 session; + /* + * the size here is variable and set by the size of our_nonce + * which must be between 16 and the name hash length. we set + * the maximum sha256 size for the greatest protection + */ + u8 our_nonce[SHA256_DIGEST_SIZE]; + u8 tpm_nonce[SHA256_DIGEST_SIZE]; + /* + * the salt is only used across the session command/response + * after that it can be used as a scratch area + */ + union { + u8 salt[EC_PT_SZ]; + /* scratch for key + IV */ + u8 scratch[AES_KEY_BYTES + AES_BLOCK_SIZE]; + }; + u8 session_key[SHA256_DIGEST_SIZE]; +}; + /* * It turns out the crypto hmac(sha256) is hard for us to consume * because it assumes a fixed key and the TPM seems to change the key @@ -113,6 +201,199 @@ static void tpm2_KDFe(u8 z[EC_PT_SZ], const char *str, u8 *pt_u, u8 *pt_v, sha256_final(&sctx, out); } +static void tpm_buf_append_salt(struct tpm_buf *buf, struct tpm_chip *chip) +{ + struct crypto_kpp *kpp; + struct kpp_request *req; + struct scatterlist s[2], d[1]; + struct ecdh p = {0}; + u8 encoded_key[EC_PT_SZ], *x, *y; + unsigned int buf_len; + + /* secret is two sized points */ + tpm_buf_append_u16(buf, (EC_PT_SZ + 2)*2); + /* + * we cheat here and append uninitialized data to form + * the points. All we care about is getting the two + * co-ordinate pointers, which will be used to overwrite + * the uninitialized data + */ + tpm_buf_append_u16(buf, EC_PT_SZ); + x = &buf->data[tpm_buf_length(buf)]; + tpm_buf_append(buf, encoded_key, EC_PT_SZ); + tpm_buf_append_u16(buf, EC_PT_SZ); + y = &buf->data[tpm_buf_length(buf)]; + tpm_buf_append(buf, encoded_key, EC_PT_SZ); + sg_init_table(s, 2); + sg_set_buf(&s[0], x, EC_PT_SZ); + sg_set_buf(&s[1], y, EC_PT_SZ); + + kpp = crypto_alloc_kpp("ecdh-nist-p256", CRYPTO_ALG_INTERNAL, 0); + if (IS_ERR(kpp)) { + dev_err(&chip->dev, "crypto ecdh allocation failed\n"); + return; + } + + buf_len = crypto_ecdh_key_len(&p); + if (sizeof(encoded_key) < buf_len) { + dev_err(&chip->dev, "salt buffer too small needs %d\n", + buf_len); + goto out; + } + crypto_ecdh_encode_key(encoded_key, buf_len, &p); + /* this generates a random private key */ + crypto_kpp_set_secret(kpp, encoded_key, buf_len); + + /* salt is now the public point of this private key */ + req = kpp_request_alloc(kpp, GFP_KERNEL); + if (!req) + goto out; + kpp_request_set_input(req, NULL, 0); + kpp_request_set_output(req, s, EC_PT_SZ*2); + crypto_kpp_generate_public_key(req); + /* + * we're not done: now we have to compute the shared secret + * which is our private key multiplied by the tpm_key public + * point, we actually only take the x point and discard the y + * point and feed it through KDFe to get the final secret salt + */ + sg_set_buf(&s[0], chip->null_ec_key_x, EC_PT_SZ); + sg_set_buf(&s[1], chip->null_ec_key_y, EC_PT_SZ); + kpp_request_set_input(req, s, EC_PT_SZ*2); + sg_init_one(d, chip->auth->salt, EC_PT_SZ); + kpp_request_set_output(req, d, EC_PT_SZ); + crypto_kpp_compute_shared_secret(req); + kpp_request_free(req); + + /* + * pass the shared secret through KDFe for salt. Note salt + * area is used both for input shared secret and output salt. + * This works because KDFe fully consumes the secret before it + * writes the salt + */ + tpm2_KDFe(chip->auth->salt, "SECRET", x, chip->null_ec_key_x, + chip->auth->salt); + + out: + crypto_free_kpp(kpp); +} +/** + * tpm2_end_auth_session() - kill the allocated auth session + * @chip: the TPM chip structure + * + * ends the session started by tpm2_start_auth_session and frees all + * the resources. Under normal conditions, + * tpm_buf_check_hmac_response() will correctly end the session if + * required, so this function is only for use in error legs that will + * bypass the normal invocation of tpm_buf_check_hmac_response(). + */ +void tpm2_end_auth_session(struct tpm_chip *chip) +{ + tpm2_flush_context(chip, chip->auth->handle); + memzero_explicit(chip->auth, sizeof(*chip->auth)); +} +EXPORT_SYMBOL(tpm2_end_auth_session); + +static int tpm2_parse_start_auth_session(struct tpm2_auth *auth, + struct tpm_buf *buf) +{ + struct tpm_header *head = (struct tpm_header *)buf->data; + u32 tot_len = be32_to_cpu(head->length); + off_t offset = TPM_HEADER_SIZE; + u32 val; + + /* we're starting after the header so adjust the length */ + tot_len -= TPM_HEADER_SIZE; + + /* should have handle plus nonce */ + if (tot_len != 4 + 2 + sizeof(auth->tpm_nonce)) + return -EINVAL; + + auth->handle = tpm_buf_read_u32(buf, &offset); + val = tpm_buf_read_u16(buf, &offset); + if (val != sizeof(auth->tpm_nonce)) + return -EINVAL; + memcpy(auth->tpm_nonce, &buf->data[offset], sizeof(auth->tpm_nonce)); + /* now compute the session key from the nonces */ + tpm2_KDFa(auth->salt, sizeof(auth->salt), "ATH", auth->tpm_nonce, + auth->our_nonce, sizeof(auth->session_key), + auth->session_key); + + return 0; +} + +/** + * tpm2_start_auth_session() - create a HMAC authentication session with the TPM + * @chip: the TPM chip structure to create the session with + * + * This function loads the NULL seed from its saved context and starts + * an authentication session on the null seed, fills in the + * @chip->auth structure to contain all the session details necessary + * for performing the HMAC, encrypt and decrypt operations and + * returns. The NULL seed is flushed before this function returns. + * + * Return: zero on success or actual error encountered. + */ +int tpm2_start_auth_session(struct tpm_chip *chip) +{ + struct tpm_buf buf; + struct tpm2_auth *auth = chip->auth; + int rc; + /* null seed context has no offset, but we must provide one */ + unsigned int offset = 0; + u32 nullkey; + + rc = tpm2_load_context(chip, chip->null_key_context, &offset, + &nullkey); + if (rc) + goto out; + + auth->session = TPM_HEADER_SIZE; + + rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_START_AUTH_SESS); + if (rc) + goto out; + + /* salt key handle */ + tpm_buf_append_u32(&buf, nullkey); + /* bind key handle */ + tpm_buf_append_u32(&buf, TPM2_RH_NULL); + /* nonce caller */ + get_random_bytes(auth->our_nonce, sizeof(auth->our_nonce)); + tpm_buf_append_u16(&buf, sizeof(auth->our_nonce)); + tpm_buf_append(&buf, auth->our_nonce, sizeof(auth->our_nonce)); + + /* append encrypted salt and squirrel away unencrypted in auth */ + tpm_buf_append_salt(&buf, chip); + /* session type (HMAC, audit or policy) */ + tpm_buf_append_u8(&buf, TPM2_SE_HMAC); + + /* symmetric encryption parameters */ + /* symmetric algorithm */ + tpm_buf_append_u16(&buf, TPM_ALG_AES); + /* bits for symmetric algorithm */ + tpm_buf_append_u16(&buf, AES_KEY_BITS); + /* symmetric algorithm mode (must be CFB) */ + tpm_buf_append_u16(&buf, TPM_ALG_CFB); + /* hash algorithm for session */ + tpm_buf_append_u16(&buf, TPM_ALG_SHA256); + + rc = tpm_transmit_cmd(chip, &buf, 0, "start auth session"); + tpm2_flush_context(chip, nullkey); + + if (rc == TPM2_RC_SUCCESS) + rc = tpm2_parse_start_auth_session(auth, &buf); + + tpm_buf_destroy(&buf); + + if (rc) + goto out; + + out: + return rc; +} +EXPORT_SYMBOL(tpm2_start_auth_session); + /** * tpm2_parse_create_primary() - parse the data returned from TPM_CC_CREATE_PRIMARY * @@ -417,5 +698,9 @@ int tpm2_sessions_init(struct tpm_chip *chip) if (rc) dev_err(&chip->dev, "TPM: security failed (NULL seed derivation): %d\n", rc); + chip->auth = kmalloc(sizeof(*chip->auth), GFP_KERNEL); + if (!chip->auth) + return -ENOMEM; + return rc; } diff --git a/include/linux/tpm.h b/include/linux/tpm.h index bc8c9a350e23..81b5a70ff80d 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -31,6 +31,14 @@ struct tpm_chip; struct trusted_key_payload; struct trusted_key_options; +/* opaque structure, holds auth session parameters like the session key */ +struct tpm2_auth; + +enum tpm2_session_types { + TPM2_SE_HMAC = 0x00, + TPM2_SE_POLICY = 0x01, + TPM2_SE_TRIAL = 0x02, +}; /* if you add a new hash to this, increment TPM_MAX_HASHES below */ enum tpm_algorithms { @@ -203,6 +211,7 @@ struct tpm_chip { u8 null_key_name[TPM2_NAME_SIZE]; u8 null_ec_key_x[EC_PT_SZ]; u8 null_ec_key_y[EC_PT_SZ]; + struct tpm2_auth *auth; #endif }; @@ -266,6 +275,7 @@ enum tpm2_command_codes { TPM2_CC_CONTEXT_LOAD = 0x0161, TPM2_CC_CONTEXT_SAVE = 0x0162, TPM2_CC_FLUSH_CONTEXT = 0x0165, + TPM2_CC_START_AUTH_SESS = 0x0176, TPM2_CC_VERIFY_SIGNATURE = 0x0177, TPM2_CC_GET_CAPABILITY = 0x017A, TPM2_CC_GET_RANDOM = 0x017B, @@ -349,16 +359,21 @@ struct tpm_buf { u32 flags; u32 length; u8 *data; + u8 handles; }; enum tpm2_object_attributes { TPM2_OA_FIXED_TPM = BIT(1), + TPM2_OA_ST_CLEAR = BIT(2), TPM2_OA_FIXED_PARENT = BIT(4), TPM2_OA_SENSITIVE_DATA_ORIGIN = BIT(5), TPM2_OA_USER_WITH_AUTH = BIT(6), + TPM2_OA_ADMIN_WITH_POLICY = BIT(7), TPM2_OA_NO_DA = BIT(10), + TPM2_OA_ENCRYPTED_DUPLICATION = BIT(11), TPM2_OA_RESTRICTED = BIT(16), TPM2_OA_DECRYPT = BIT(17), + TPM2_OA_SIGN = BIT(18), }; /* @@ -378,6 +393,11 @@ enum tpm2_object_attributes { enum tpm2_session_attributes { TPM2_SA_CONTINUE_SESSION = BIT(0), + TPM2_SA_AUDIT_EXCLUSIVE = BIT(1), + TPM2_SA_AUDIT_RESET = BIT(3), + TPM2_SA_DECRYPT = BIT(5), + TPM2_SA_ENCRYPT = BIT(6), + TPM2_SA_AUDIT = BIT(7), }; struct tpm2_hash { @@ -469,4 +489,18 @@ static inline void tpm_buf_append_empty_auth(struct tpm_buf *buf, u32 handle) { } #endif +#ifdef CONFIG_TCG_TPM2_HMAC + +int tpm2_start_auth_session(struct tpm_chip *chip); +void tpm2_end_auth_session(struct tpm_chip *chip); +#else +static inline int tpm2_start_auth_session(struct tpm_chip *chip) +{ + return 0; +} +static inline void tpm2_end_auth_session(struct tpm_chip *chip) +{ +} +#endif /* CONFIG_TCG_TPM2_HMAC */ + #endif From patchwork Mon Apr 29 20:28:04 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647686 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6AA16158A11; Mon, 29 Apr 2024 20:30:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422639; cv=none; b=YtUqTkdXb1u4b4g3kiSEhwvj/Br3edHUnPTG4OIPYwiwNWZQx7cYRDEhTUW4PNDk/A7IqdfHhVFYjgh1T2ALaZtP71rSlR2WLELvXd/7nZlmsPiBuAhIdIs+YXK2l50Gmng6XONQVHek3Pqj2MImzjHxxF7cRtfeb9MsI4ppKHI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422639; c=relaxed/simple; bh=v1kIbEq+ZE0V/88P6CsDLFkFP1qZLMUU2+z4E1qDoG4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=QmHeZ8Y86g4k6dbSdT5UveCzb2VlUUFvE8RTu8Ec1tXv0QMJYX7XHHE5qeseI/o/prjlT4KIlMKCVFDbF5x234+hNHPl8frpePXIOis9sWIwzDGLon2PwmK6gnF1GtiTnVt7mLij6NDWx5opxeGQiyGz8PUyFjzrmhr+0Vb5+4A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=GryJGTex; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="GryJGTex" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422637; bh=v1kIbEq+ZE0V/88P6CsDLFkFP1qZLMUU2+z4E1qDoG4=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=GryJGTexflgWTBsfJLpC2+c9379TRma0pWtiMxWAS4CYh+EEIGWmyBXJ1DfPbxvkU 2FmWwMZ3bBkRxAnnWdh6e/esHCdjzXLPRiRib5vJYOiWNGTfK7B3sAtOV9MihvNKzU PzjXSjRMxebJdqf3hGG7NHu9RV22pYPqVrVZWBlU= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id D962C1281D87; Mon, 29 Apr 2024 16:30:37 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id JjT0fDUDl0IS; Mon, 29 Apr 2024 16:30:37 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 4AF9012819F3; Mon, 29 Apr 2024 16:30:37 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 15/22] tpm: Add HMAC session name/handle append Date: Mon, 29 Apr 2024 16:28:04 -0400 Message-Id: <20240429202811.13643-16-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Add tpm2_append_name() for appending to the handle area of the TPM command. When TPM_BUS_SECURITY is enabled and HMAC sessions are in use this adds the standard u32 handle to the buffer but additionally records the name of the object which must be used as part of the HMAC computation. The name of certain object types (volatile and permanent handles and NV indexes) is a hash of the public area of the object. Since this hash is not known ahead of time, it must be requested from the TPM using TPM2_ReadPublic() (which cannot be HMAC protected, but if an interposer lies about it, the HMAC check will fail and the problem will be detected). Signed-off-by: James Bottomley Reviewed-by: Ard Biesheuvel # crypto API parts Reviewed-by: Jarkko Sakkinen --- v6: split into new patch, update config variable v7: add tpm2_ prefix v8: minor updates --- drivers/char/tpm/tpm2-sessions.c | 129 +++++++++++++++++++++++++++++++ include/linux/tpm.h | 26 +++++++ 2 files changed, 155 insertions(+) diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c index 71b3c0e75760..99eb048f18c8 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -49,6 +49,11 @@ * Under normal operation this function is done by * tpm_buf_check_hmac_response(), so this is only to be used on * error legs where the latter is not executed. + * tpm_buf_append_name() to add a handle to the buffer. This must be + * used in place of the usual tpm_buf_append_u32() for adding + * handles because handles have to be processed specially when + * calculating the HMAC. In particular, for NV, volatile and + * permanent objects you now need to provide the name. */ #include "tpm.h" @@ -60,6 +65,9 @@ #include #include +/* maximum number of names the TPM must remember for authorization */ +#define AUTH_MAX_NAMES 3 + /* * This is the structure that carries all the auth information (like * session handle, nonces, session key and auth) from use to use it is @@ -96,8 +104,31 @@ struct tpm2_auth { u8 scratch[AES_KEY_BYTES + AES_BLOCK_SIZE]; }; u8 session_key[SHA256_DIGEST_SIZE]; + + /* + * memory for three authorization handles. We know them by + * handle, but they are part of the session by name, which + * we must compute and remember + */ + u32 name_h[AUTH_MAX_NAMES]; + u8 name[AUTH_MAX_NAMES][2 + SHA512_DIGEST_SIZE]; }; +/* + * Name Size based on TPM algorithm (assumes no hash bigger than 255) + */ +static u8 name_size(const u8 *name) +{ + static u8 size_map[] = { + [TPM_ALG_SHA1] = SHA1_DIGEST_SIZE, + [TPM_ALG_SHA256] = SHA256_DIGEST_SIZE, + [TPM_ALG_SHA384] = SHA384_DIGEST_SIZE, + [TPM_ALG_SHA512] = SHA512_DIGEST_SIZE, + }; + u16 alg = get_unaligned_be16(name); + return size_map[alg] + 2; +} + /* * It turns out the crypto hmac(sha256) is hard for us to consume * because it assumes a fixed key and the TPM seems to change the key @@ -277,6 +308,104 @@ static void tpm_buf_append_salt(struct tpm_buf *buf, struct tpm_chip *chip) out: crypto_free_kpp(kpp); } + +static int tpm2_parse_read_public(char *name, struct tpm_buf *buf) +{ + struct tpm_header *head = (struct tpm_header *)buf->data; + off_t offset = TPM_HEADER_SIZE; + u32 tot_len = be32_to_cpu(head->length); + u32 val; + + /* we're starting after the header so adjust the length */ + tot_len -= TPM_HEADER_SIZE; + + /* skip public */ + val = tpm_buf_read_u16(buf, &offset); + if (val > tot_len) + return -EINVAL; + offset += val; + /* name */ + val = tpm_buf_read_u16(buf, &offset); + if (val != name_size(&buf->data[offset])) + return -EINVAL; + memcpy(name, &buf->data[offset], val); + /* forget the rest */ + return 0; +} + +static int tpm2_read_public(struct tpm_chip *chip, u32 handle, char *name) +{ + struct tpm_buf buf; + int rc; + + rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_READ_PUBLIC); + if (rc) + return rc; + + tpm_buf_append_u32(&buf, handle); + rc = tpm_transmit_cmd(chip, &buf, 0, "read public"); + if (rc == TPM2_RC_SUCCESS) + rc = tpm2_parse_read_public(name, &buf); + + tpm_buf_destroy(&buf); + + return rc; +} + +/** + * tpm_buf_append_name() - add a handle area to the buffer + * @chip: the TPM chip structure + * @buf: The buffer to be appended + * @handle: The handle to be appended + * @name: The name of the handle (may be NULL) + * + * In order to compute session HMACs, we need to know the names of the + * objects pointed to by the handles. For most objects, this is simply + * the actual 4 byte handle or an empty buf (in these cases @name + * should be NULL) but for volatile objects, permanent objects and NV + * areas, the name is defined as the hash (according to the name + * algorithm which should be set to sha256) of the public area to + * which the two byte algorithm id has been appended. For these + * objects, the @name pointer should point to this. If a name is + * required but @name is NULL, then TPM2_ReadPublic() will be called + * on the handle to obtain the name. + * + * As with most tpm_buf operations, success is assumed because failure + * will be caused by an incorrect programming model and indicated by a + * kernel message. + */ +void tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf, + u32 handle, u8 *name) +{ + enum tpm2_mso_type mso = tpm2_handle_mso(handle); + struct tpm2_auth *auth = chip->auth; + int slot; + + slot = (tpm_buf_length(buf) - TPM_HEADER_SIZE)/4; + if (slot >= AUTH_MAX_NAMES) { + dev_err(&chip->dev, "TPM: too many handles\n"); + return; + } + WARN(auth->session != tpm_buf_length(buf), + "name added in wrong place\n"); + tpm_buf_append_u32(buf, handle); + auth->session += 4; + + if (mso == TPM2_MSO_PERSISTENT || + mso == TPM2_MSO_VOLATILE || + mso == TPM2_MSO_NVRAM) { + if (!name) + tpm2_read_public(chip, handle, auth->name[slot]); + } else { + if (name) + dev_err(&chip->dev, "TPM: Handle does not require name but one is specified\n"); + } + + auth->name_h[slot] = handle; + if (name) + memcpy(auth->name[slot], name, name_size(name)); +} +EXPORT_SYMBOL(tpm_buf_append_name); /** * tpm2_end_auth_session() - kill the allocated auth session * @chip: the TPM chip structure diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 81b5a70ff80d..31c2065fcd35 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -275,6 +275,7 @@ enum tpm2_command_codes { TPM2_CC_CONTEXT_LOAD = 0x0161, TPM2_CC_CONTEXT_SAVE = 0x0162, TPM2_CC_FLUSH_CONTEXT = 0x0165, + TPM2_CC_READ_PUBLIC = 0x0173, TPM2_CC_START_AUTH_SESS = 0x0176, TPM2_CC_VERIFY_SIGNATURE = 0x0177, TPM2_CC_GET_CAPABILITY = 0x017A, @@ -292,6 +293,21 @@ enum tpm2_permanent_handles { TPM2_RS_PW = 0x40000009, }; +/* Most Significant Octet for key types */ +enum tpm2_mso_type { + TPM2_MSO_NVRAM = 0x01, + TPM2_MSO_SESSION = 0x02, + TPM2_MSO_POLICY = 0x03, + TPM2_MSO_PERMANENT = 0x40, + TPM2_MSO_VOLATILE = 0x80, + TPM2_MSO_PERSISTENT = 0x81, +}; + +static inline enum tpm2_mso_type tpm2_handle_mso(u32 handle) +{ + return handle >> 24; +} + enum tpm2_capabilities { TPM2_CAP_HANDLES = 1, TPM2_CAP_COMMANDS = 2, @@ -492,6 +508,8 @@ static inline void tpm_buf_append_empty_auth(struct tpm_buf *buf, u32 handle) #ifdef CONFIG_TCG_TPM2_HMAC int tpm2_start_auth_session(struct tpm_chip *chip); +void tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf, + u32 handle, u8 *name); void tpm2_end_auth_session(struct tpm_chip *chip); #else static inline int tpm2_start_auth_session(struct tpm_chip *chip) @@ -501,6 +519,14 @@ static inline int tpm2_start_auth_session(struct tpm_chip *chip) static inline void tpm2_end_auth_session(struct tpm_chip *chip) { } +static inline void tpm_buf_append_name(struct tpm_chip *chip, + struct tpm_buf *buf, + u32 handle, u8 *name) +{ + tpm_buf_append_u32(buf, handle); + /* count the number of handles in the upper bits of flags */ + buf->handles++; +} #endif /* CONFIG_TCG_TPM2_HMAC */ #endif From patchwork Mon Apr 29 20:28:05 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647687 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4410D15B112; Mon, 29 Apr 2024 20:30:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422649; cv=none; b=l549IEACpam0BpCSLH17E+XMKJf4VJt/wygfNEmVsOxTUVNkboO8Tf71YjlHZgkdlo6tcIwV9aK+ejE3VBZmiyekaKFM9Fe9GHdwnjHkRmS17Ib5IbYvV10xaFc435ChK7IBHOU2Jo3BwcK+SFVjB/kG66KZrPyatsiPggqCmOY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422649; c=relaxed/simple; bh=slu9FUjYGHC1AlJJrB13ItEtdfsMTziqFWhPZ9f5Enc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=etOiOXM6a2oYoLjgjZLMNPFo7S+zb4nrTAEvCxluViHAlqEBPit8uLCM4evC+yii/dPY9ytW/NmjBDm2cA07JmjnGGk8iRlJZk0MkAN2i43sZVa5FntmT+pQFNAC1tVz64bftTZRVI4lOiXfIlLc+3TFgYRuMPG3L0XzFgBhEs0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=KWUkM7th; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="KWUkM7th" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422646; bh=slu9FUjYGHC1AlJJrB13ItEtdfsMTziqFWhPZ9f5Enc=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=KWUkM7thbgt3JOoK0Mz+YXM/dMbQyp9vtKqrgzTP+4CryscJoY/VEINwOJpdGrmS7 h+6NYWuOcKGY0Wbdqgr7bfwPNq7yoopyK2+ZKJddGqhHCFzQNSSNghEx/Phv/3BfVy K9uCwMsiA5dO0MlMpF4l19wCmpz6wxDKAYNLai/k= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id D6AD61281D87; Mon, 29 Apr 2024 16:30:46 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id lt7_CRTMEFr1; Mon, 29 Apr 2024 16:30:46 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 3F97512819F3; Mon, 29 Apr 2024 16:30:46 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 16/22] tpm: Add the rest of the session HMAC API Date: Mon, 29 Apr 2024 16:28:05 -0400 Message-Id: <20240429202811.13643-17-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The final pieces of the HMAC API are for manipulating the session area of the command. To add an authentication HMAC session tpm_buf_append_hmac_session() is called where tpm2_append_auth() would go. If a non empty password is passed in, this is correctly added to the HMAC to prove knowledge of it without revealing it. Note that if the session is only used to encrypt or decrypt parameters (no authentication) then tpm_buf_append_hmac_session_opt() must be used instead. This functions identically to tpm_buf_append_hmac_session() when TPM_BUS_SECURITY is enabled, but differently when it isn't, because effectively nothing is appended to the session area. Next the parameters should be filled in for the command and finally tpm_buf_fill_hmac_session() is called immediately prior to transmitting the command which computes the correct HMAC and places it in the command at the session location in the tpm buffer Finally, after tpm_transmit_cmd() is called, tpm_buf_check_hmac_response() is called to check that the returned HMAC matched and collect the new state for the next use of the session, if any. The features of the session are controlled by the session attributes set in tpm_buf_append_hmac_session(). If TPM2_SA_CONTINUE_SESSION is not specified, the session will be flushed and the tpm2_auth structure freed in tpm_buf_check_hmac_response(); otherwise the session may be used again. Parameter encryption is specified by or'ing the flag TPM2_SA_DECRYPT and response encryption by or'ing the flag TPM2_SA_ENCRYPT. the various encryptions will be taken care of by tpm_buf_fill_hmac_session() and tpm_buf_check_hmac_response() respectively. Signed-off-by: James Bottomley Reviewed-by: Ard Biesheuvel # crypto API parts Reviewed-by: Jarkko Sakkinen --- v6: split into new patch, update config variable v7: add memzero_explicit v8: minor updates --- drivers/char/tpm/tpm2-sessions.c | 400 +++++++++++++++++++++++++++++++ include/linux/tpm.h | 69 ++++++ 2 files changed, 469 insertions(+) diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c index 99eb048f18c8..3c97d3d5e00e 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -54,6 +54,18 @@ * handles because handles have to be processed specially when * calculating the HMAC. In particular, for NV, volatile and * permanent objects you now need to provide the name. + * tpm_buf_append_hmac_session() which appends the hmac session to the + * buf in the same way tpm_buf_append_auth does(). + * tpm_buf_fill_hmac_session() This calculates the correct hash and + * places it in the buffer. It must be called after the complete + * command buffer is finalized so it can fill in the correct HMAC + * based on the parameters. + * tpm_buf_check_hmac_response() which checks the session response in + * the buffer and calculates what it should be. If there's a + * mismatch it will log a warning and return an error. If + * tpm_buf_append_hmac_session() did not specify + * TPM_SA_CONTINUE_SESSION then the session will be closed (if it + * hasn't been consumed) and the auth structure freed. */ #include "tpm.h" @@ -103,7 +115,23 @@ struct tpm2_auth { /* scratch for key + IV */ u8 scratch[AES_KEY_BYTES + AES_BLOCK_SIZE]; }; + /* + * the session key and passphrase are the same size as the + * name digest (sha256 again). The session key is constant + * for the use of the session and the passphrase can change + * with every invocation. + * + * Note: these fields must be adjacent and in this order + * because several HMAC/KDF schemes use the combination of the + * session_key and passphrase. + */ u8 session_key[SHA256_DIGEST_SIZE]; + u8 passphrase[SHA256_DIGEST_SIZE]; + int passphrase_len; + struct crypto_aes_ctx aes_ctx; + /* saved session attributes: */ + u8 attrs; + __be32 ordinal; /* * memory for three authorization handles. We know them by @@ -309,6 +337,230 @@ static void tpm_buf_append_salt(struct tpm_buf *buf, struct tpm_chip *chip) crypto_free_kpp(kpp); } +/** + * tpm_buf_append_hmac_session() - Append a TPM session element + * @chip: the TPM chip structure + * @buf: The buffer to be appended + * @attributes: The session attributes + * @passphrase: The session authority (NULL if none) + * @passphrase_len: The length of the session authority (0 if none) + * + * This fills in a session structure in the TPM command buffer, except + * for the HMAC which cannot be computed until the command buffer is + * complete. The type of session is controlled by the @attributes, + * the main ones of which are TPM2_SA_CONTINUE_SESSION which means the + * session won't terminate after tpm_buf_check_hmac_response(), + * TPM2_SA_DECRYPT which means this buffers first parameter should be + * encrypted with a session key and TPM2_SA_ENCRYPT, which means the + * response buffer's first parameter needs to be decrypted (confusing, + * but the defines are written from the point of view of the TPM). + * + * Any session appended by this command must be finalized by calling + * tpm_buf_fill_hmac_session() otherwise the HMAC will be incorrect + * and the TPM will reject the command. + * + * As with most tpm_buf operations, success is assumed because failure + * will be caused by an incorrect programming model and indicated by a + * kernel message. + */ +void tpm_buf_append_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf, + u8 attributes, u8 *passphrase, + int passphrase_len) +{ + u8 nonce[SHA256_DIGEST_SIZE]; + u32 len; + struct tpm2_auth *auth = chip->auth; + + /* + * The Architecture Guide requires us to strip trailing zeros + * before computing the HMAC + */ + while (passphrase && passphrase_len > 0 + && passphrase[passphrase_len - 1] == '\0') + passphrase_len--; + + auth->attrs = attributes; + auth->passphrase_len = passphrase_len; + if (passphrase_len) + memcpy(auth->passphrase, passphrase, passphrase_len); + + if (auth->session != tpm_buf_length(buf)) { + /* we're not the first session */ + len = get_unaligned_be32(&buf->data[auth->session]); + if (4 + len + auth->session != tpm_buf_length(buf)) { + WARN(1, "session length mismatch, cannot append"); + return; + } + + /* add our new session */ + len += 9 + 2 * SHA256_DIGEST_SIZE; + put_unaligned_be32(len, &buf->data[auth->session]); + } else { + tpm_buf_append_u32(buf, 9 + 2 * SHA256_DIGEST_SIZE); + } + + /* random number for our nonce */ + get_random_bytes(nonce, sizeof(nonce)); + memcpy(auth->our_nonce, nonce, sizeof(nonce)); + tpm_buf_append_u32(buf, auth->handle); + /* our new nonce */ + tpm_buf_append_u16(buf, SHA256_DIGEST_SIZE); + tpm_buf_append(buf, nonce, SHA256_DIGEST_SIZE); + tpm_buf_append_u8(buf, auth->attrs); + /* and put a placeholder for the hmac */ + tpm_buf_append_u16(buf, SHA256_DIGEST_SIZE); + tpm_buf_append(buf, nonce, SHA256_DIGEST_SIZE); +} +EXPORT_SYMBOL(tpm_buf_append_hmac_session); + +/** + * tpm_buf_fill_hmac_session() - finalize the session HMAC + * @chip: the TPM chip structure + * @buf: The buffer to be appended + * + * This command must not be called until all of the parameters have + * been appended to @buf otherwise the computed HMAC will be + * incorrect. + * + * This function computes and fills in the session HMAC using the + * session key and, if TPM2_SA_DECRYPT was specified, computes the + * encryption key and encrypts the first parameter of the command + * buffer with it. + * + * As with most tpm_buf operations, success is assumed because failure + * will be caused by an incorrect programming model and indicated by a + * kernel message. + */ +void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf) +{ + u32 cc, handles, val; + struct tpm2_auth *auth = chip->auth; + int i; + struct tpm_header *head = (struct tpm_header *)buf->data; + off_t offset_s = TPM_HEADER_SIZE, offset_p; + u8 *hmac = NULL; + u32 attrs; + u8 cphash[SHA256_DIGEST_SIZE]; + struct sha256_state sctx; + + /* save the command code in BE format */ + auth->ordinal = head->ordinal; + + cc = be32_to_cpu(head->ordinal); + + i = tpm2_find_cc(chip, cc); + if (i < 0) { + dev_err(&chip->dev, "Command 0x%x not found in TPM\n", cc); + return; + } + attrs = chip->cc_attrs_tbl[i]; + + handles = (attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0); + + /* + * just check the names, it's easy to make mistakes. This + * would happen if someone added a handle via + * tpm_buf_append_u32() instead of tpm_buf_append_name() + */ + for (i = 0; i < handles; i++) { + u32 handle = tpm_buf_read_u32(buf, &offset_s); + + if (auth->name_h[i] != handle) { + dev_err(&chip->dev, "TPM: handle %d wrong for name\n", + i); + return; + } + } + /* point offset_s to the start of the sessions */ + val = tpm_buf_read_u32(buf, &offset_s); + /* point offset_p to the start of the parameters */ + offset_p = offset_s + val; + for (i = 1; offset_s < offset_p; i++) { + u32 handle = tpm_buf_read_u32(buf, &offset_s); + u16 len; + u8 a; + + /* nonce (already in auth) */ + len = tpm_buf_read_u16(buf, &offset_s); + offset_s += len; + + a = tpm_buf_read_u8(buf, &offset_s); + + len = tpm_buf_read_u16(buf, &offset_s); + if (handle == auth->handle && auth->attrs == a) { + hmac = &buf->data[offset_s]; + /* + * save our session number so we know which + * session in the response belongs to us + */ + auth->session = i; + } + + offset_s += len; + } + if (offset_s != offset_p) { + dev_err(&chip->dev, "TPM session length is incorrect\n"); + return; + } + if (!hmac) { + dev_err(&chip->dev, "TPM could not find HMAC session\n"); + return; + } + + /* encrypt before HMAC */ + if (auth->attrs & TPM2_SA_DECRYPT) { + u16 len; + + /* need key and IV */ + tpm2_KDFa(auth->session_key, SHA256_DIGEST_SIZE + + auth->passphrase_len, "CFB", auth->our_nonce, + auth->tpm_nonce, AES_KEY_BYTES + AES_BLOCK_SIZE, + auth->scratch); + + len = tpm_buf_read_u16(buf, &offset_p); + aes_expandkey(&auth->aes_ctx, auth->scratch, AES_KEY_BYTES); + aescfb_encrypt(&auth->aes_ctx, &buf->data[offset_p], + &buf->data[offset_p], len, + auth->scratch + AES_KEY_BYTES); + /* reset p to beginning of parameters for HMAC */ + offset_p -= 2; + } + + sha256_init(&sctx); + /* ordinal is already BE */ + sha256_update(&sctx, (u8 *)&head->ordinal, sizeof(head->ordinal)); + /* add the handle names */ + for (i = 0; i < handles; i++) { + enum tpm2_mso_type mso = tpm2_handle_mso(auth->name_h[i]); + + if (mso == TPM2_MSO_PERSISTENT || + mso == TPM2_MSO_VOLATILE || + mso == TPM2_MSO_NVRAM) { + sha256_update(&sctx, auth->name[i], + name_size(auth->name[i])); + } else { + __be32 h = cpu_to_be32(auth->name_h[i]); + + sha256_update(&sctx, (u8 *)&h, 4); + } + } + if (offset_s != tpm_buf_length(buf)) + sha256_update(&sctx, &buf->data[offset_s], + tpm_buf_length(buf) - offset_s); + sha256_final(&sctx, cphash); + + /* now calculate the hmac */ + tpm2_hmac_init(&sctx, auth->session_key, sizeof(auth->session_key) + + auth->passphrase_len); + sha256_update(&sctx, cphash, sizeof(cphash)); + sha256_update(&sctx, auth->our_nonce, sizeof(auth->our_nonce)); + sha256_update(&sctx, auth->tpm_nonce, sizeof(auth->tpm_nonce)); + sha256_update(&sctx, &auth->attrs, 1); + tpm2_hmac_final(&sctx, auth->session_key, sizeof(auth->session_key) + + auth->passphrase_len, hmac); +} +EXPORT_SYMBOL(tpm_buf_fill_hmac_session); + static int tpm2_parse_read_public(char *name, struct tpm_buf *buf) { struct tpm_header *head = (struct tpm_header *)buf->data; @@ -406,6 +658,154 @@ void tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf, memcpy(auth->name[slot], name, name_size(name)); } EXPORT_SYMBOL(tpm_buf_append_name); + +/** + * tpm_buf_check_hmac_response() - check the TPM return HMAC for correctness + * @chip: the TPM chip structure + * @buf: the original command buffer (which now contains the response) + * @rc: the return code from tpm_transmit_cmd + * + * If @rc is non zero, @buf may not contain an actual return, so @rc + * is passed through as the return and the session cleaned up and + * de-allocated if required (this is required if + * TPM2_SA_CONTINUE_SESSION was not specified as a session flag). + * + * If @rc is zero, the response HMAC is computed against the returned + * @buf and matched to the TPM one in the session area. If there is a + * mismatch, an error is logged and -EINVAL returned. + * + * The reason for this is that the command issue and HMAC check + * sequence should look like: + * + * rc = tpm_transmit_cmd(...); + * rc = tpm_buf_check_hmac_response(&buf, auth, rc); + * if (rc) + * ... + * + * Which is easily layered into the current contrl flow. + * + * Returns: 0 on success or an error. + */ +int tpm_buf_check_hmac_response(struct tpm_chip *chip, struct tpm_buf *buf, + int rc) +{ + struct tpm_header *head = (struct tpm_header *)buf->data; + struct tpm2_auth *auth = chip->auth; + off_t offset_s, offset_p; + u8 rphash[SHA256_DIGEST_SIZE]; + u32 attrs; + struct sha256_state sctx; + u16 tag = be16_to_cpu(head->tag); + u32 cc = be32_to_cpu(auth->ordinal); + int parm_len, len, i, handles; + + if (auth->session >= TPM_HEADER_SIZE) { + WARN(1, "tpm session not filled correctly\n"); + goto out; + } + + if (rc != 0) + /* pass non success rc through and close the session */ + goto out; + + rc = -EINVAL; + if (tag != TPM2_ST_SESSIONS) { + dev_err(&chip->dev, "TPM: HMAC response check has no sessions tag\n"); + goto out; + } + + i = tpm2_find_cc(chip, cc); + if (i < 0) + goto out; + attrs = chip->cc_attrs_tbl[i]; + handles = (attrs >> TPM2_CC_ATTR_RHANDLE) & 1; + + /* point to area beyond handles */ + offset_s = TPM_HEADER_SIZE + handles * 4; + parm_len = tpm_buf_read_u32(buf, &offset_s); + offset_p = offset_s; + offset_s += parm_len; + /* skip over any sessions before ours */ + for (i = 0; i < auth->session - 1; i++) { + len = tpm_buf_read_u16(buf, &offset_s); + offset_s += len + 1; + len = tpm_buf_read_u16(buf, &offset_s); + offset_s += len; + } + /* TPM nonce */ + len = tpm_buf_read_u16(buf, &offset_s); + if (offset_s + len > tpm_buf_length(buf)) + goto out; + if (len != SHA256_DIGEST_SIZE) + goto out; + memcpy(auth->tpm_nonce, &buf->data[offset_s], len); + offset_s += len; + attrs = tpm_buf_read_u8(buf, &offset_s); + len = tpm_buf_read_u16(buf, &offset_s); + if (offset_s + len != tpm_buf_length(buf)) + goto out; + if (len != SHA256_DIGEST_SIZE) + goto out; + /* + * offset_s points to the HMAC. now calculate comparison, beginning + * with rphash + */ + sha256_init(&sctx); + /* yes, I know this is now zero, but it's what the standard says */ + sha256_update(&sctx, (u8 *)&head->return_code, + sizeof(head->return_code)); + /* ordinal is already BE */ + sha256_update(&sctx, (u8 *)&auth->ordinal, sizeof(auth->ordinal)); + sha256_update(&sctx, &buf->data[offset_p], parm_len); + sha256_final(&sctx, rphash); + + /* now calculate the hmac */ + tpm2_hmac_init(&sctx, auth->session_key, sizeof(auth->session_key) + + auth->passphrase_len); + sha256_update(&sctx, rphash, sizeof(rphash)); + sha256_update(&sctx, auth->tpm_nonce, sizeof(auth->tpm_nonce)); + sha256_update(&sctx, auth->our_nonce, sizeof(auth->our_nonce)); + sha256_update(&sctx, &auth->attrs, 1); + /* we're done with the rphash, so put our idea of the hmac there */ + tpm2_hmac_final(&sctx, auth->session_key, sizeof(auth->session_key) + + auth->passphrase_len, rphash); + if (memcmp(rphash, &buf->data[offset_s], SHA256_DIGEST_SIZE) == 0) { + rc = 0; + } else { + dev_err(&chip->dev, "TPM: HMAC check failed\n"); + goto out; + } + + /* now do response decryption */ + if (auth->attrs & TPM2_SA_ENCRYPT) { + /* need key and IV */ + tpm2_KDFa(auth->session_key, SHA256_DIGEST_SIZE + + auth->passphrase_len, "CFB", auth->tpm_nonce, + auth->our_nonce, AES_KEY_BYTES + AES_BLOCK_SIZE, + auth->scratch); + + len = tpm_buf_read_u16(buf, &offset_p); + aes_expandkey(&auth->aes_ctx, auth->scratch, AES_KEY_BYTES); + aescfb_decrypt(&auth->aes_ctx, &buf->data[offset_p], + &buf->data[offset_p], len, + auth->scratch + AES_KEY_BYTES); + } + + out: + if ((auth->attrs & TPM2_SA_CONTINUE_SESSION) == 0) { + if (rc) + /* manually close the session if it wasn't consumed */ + tpm2_flush_context(chip, auth->handle); + memzero_explicit(auth, sizeof(*auth)); + } else { + /* reset for next use */ + auth->session = TPM_HEADER_SIZE; + } + + return rc; +} +EXPORT_SYMBOL(tpm_buf_check_hmac_response); + /** * tpm2_end_auth_session() - kill the allocated auth session * @chip: the TPM chip structure diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 31c2065fcd35..dd4d6a6158c4 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -510,8 +510,25 @@ static inline void tpm_buf_append_empty_auth(struct tpm_buf *buf, u32 handle) int tpm2_start_auth_session(struct tpm_chip *chip); void tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf, u32 handle, u8 *name); +void tpm_buf_append_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf, + u8 attributes, u8 *passphrase, + int passphraselen); +static inline void tpm_buf_append_hmac_session_opt(struct tpm_chip *chip, + struct tpm_buf *buf, + u8 attributes, + u8 *passphrase, + int passphraselen) +{ + tpm_buf_append_hmac_session(chip, buf, attributes, passphrase, + passphraselen); +} +void tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf); +int tpm_buf_check_hmac_response(struct tpm_chip *chip, struct tpm_buf *buf, + int rc); void tpm2_end_auth_session(struct tpm_chip *chip); #else +#include + static inline int tpm2_start_auth_session(struct tpm_chip *chip) { return 0; @@ -527,6 +544,58 @@ static inline void tpm_buf_append_name(struct tpm_chip *chip, /* count the number of handles in the upper bits of flags */ buf->handles++; } +static inline void tpm_buf_append_hmac_session(struct tpm_chip *chip, + struct tpm_buf *buf, + u8 attributes, u8 *passphrase, + int passphraselen) +{ + /* offset tells us where the sessions area begins */ + int offset = buf->handles * 4 + TPM_HEADER_SIZE; + u32 len = 9 + passphraselen; + + if (tpm_buf_length(buf) != offset) { + /* not the first session so update the existing length */ + len += get_unaligned_be32(&buf->data[offset]); + put_unaligned_be32(len, &buf->data[offset]); + } else { + tpm_buf_append_u32(buf, len); + } + /* auth handle */ + tpm_buf_append_u32(buf, TPM2_RS_PW); + /* nonce */ + tpm_buf_append_u16(buf, 0); + /* attributes */ + tpm_buf_append_u8(buf, 0); + /* passphrase */ + tpm_buf_append_u16(buf, passphraselen); + tpm_buf_append(buf, passphrase, passphraselen); +} +static inline void tpm_buf_append_hmac_session_opt(struct tpm_chip *chip, + struct tpm_buf *buf, + u8 attributes, + u8 *passphrase, + int passphraselen) +{ + int offset = buf->handles * 4 + TPM_HEADER_SIZE; + struct tpm_header *head = (struct tpm_header *) buf->data; + + /* + * if the only sessions are optional, the command tag + * must change to TPM2_ST_NO_SESSIONS + */ + if (tpm_buf_length(buf) == offset) + head->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS); +} +static inline void tpm_buf_fill_hmac_session(struct tpm_chip *chip, + struct tpm_buf *buf) +{ +} +static inline int tpm_buf_check_hmac_response(struct tpm_chip *chip, + struct tpm_buf *buf, + int rc) +{ + return rc; +} #endif /* CONFIG_TCG_TPM2_HMAC */ #endif From patchwork Mon Apr 29 20:28:06 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647688 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8289415DBC8; Mon, 29 Apr 2024 20:30:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422657; cv=none; b=Oucn7nf6NAA5CZ0fuf81WRPUVVTsqREXsF4o7vTYQ/MkrQUdTt724X8TzEbv5leE0D+O2L5qqnv+Ir9Q+Oa/x/01NWtpoyuj61q1Xh9pJV11uP2TOkA40kzfN5EjfNc/ilmhHXtsIqd85VY57wxC2NGr/ilL4GyMzL91/GD4zMw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422657; c=relaxed/simple; bh=BkLyBAyuRrKe9xAril8jS648H4kvAAKXrIJmeVCqvzA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=NyI/Nonz7+ZQCwZOQfjBeY+vPraCN/S4WaPkRYrKqfytGKkQfbetw0T/XGCdYgRWy19yFL/STDgEnmh4JCCtRs1dXmWr9fiNzms6Z7aMo+67OF8f85e8HOvDUR4rLWEHFsr4UZWDZ8oQ3UCACMRuJwM2AeqjMB7Ai4NQc3UC5uM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=WZBJs6Of; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="WZBJs6Of" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422655; bh=BkLyBAyuRrKe9xAril8jS648H4kvAAKXrIJmeVCqvzA=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=WZBJs6OfUkxjRebTvS+qg/6D7aO0TrQcojbKviBisrixq/eTFPYP/HLnJ49+zwu1U x7RXoUg8ead9mUhnRUOR99xUl+OGT3mdlItFBUP9Vdz3spA0RFWiG9Rt31kl88GvXJ aiPwEi8di0ULlVvVxBr3sBm3sFFFwJ0k253OLK1U= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id E28831281ED0; Mon, 29 Apr 2024 16:30:55 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id JLgvic1UlTaK; Mon, 29 Apr 2024 16:30:55 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 597E21281D87; Mon, 29 Apr 2024 16:30:55 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 17/22] tpm: add hmac checks to tpm2_pcr_extend() Date: Mon, 29 Apr 2024 16:28:06 -0400 Message-Id: <20240429202811.13643-18-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 tpm2_pcr_extend() is used by trusted keys to extend a PCR to prevent a key from being re-loaded until the next reboot. To use this functionality securely, that extend must be protected by a session hmac. This patch adds HMAC protection so tampering with the tpm2_pcr_extend() command in flight is detected. Signed-off-by: James Bottomley Reviewed-by: Jarkko Sakkinen --- v7: add review --- drivers/char/tpm/tpm2-cmd.c | 27 ++++++++++----------------- 1 file changed, 10 insertions(+), 17 deletions(-) diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index b0e72fb563d9..a53a843294ed 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -216,13 +216,6 @@ int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx, return rc; } -struct tpm2_null_auth_area { - __be32 handle; - __be16 nonce_size; - u8 attributes; - __be16 auth_size; -} __packed; - /** * tpm2_pcr_extend() - extend a PCR value * @@ -236,24 +229,22 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, struct tpm_digest *digests) { struct tpm_buf buf; - struct tpm2_null_auth_area auth_area; int rc; int i; - rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND); + rc = tpm2_start_auth_session(chip); if (rc) return rc; - tpm_buf_append_u32(&buf, pcr_idx); + rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND); + if (rc) { + tpm2_end_auth_session(chip); + return rc; + } - auth_area.handle = cpu_to_be32(TPM2_RS_PW); - auth_area.nonce_size = 0; - auth_area.attributes = 0; - auth_area.auth_size = 0; + tpm_buf_append_name(chip, &buf, pcr_idx, NULL); + tpm_buf_append_hmac_session(chip, &buf, 0, NULL, 0); - tpm_buf_append_u32(&buf, sizeof(struct tpm2_null_auth_area)); - tpm_buf_append(&buf, (const unsigned char *)&auth_area, - sizeof(auth_area)); tpm_buf_append_u32(&buf, chip->nr_allocated_banks); for (i = 0; i < chip->nr_allocated_banks; i++) { @@ -262,7 +253,9 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, chip->allocated_banks[i].digest_size); } + tpm_buf_fill_hmac_session(chip, &buf); rc = tpm_transmit_cmd(chip, &buf, 0, "attempting extend a PCR value"); + rc = tpm_buf_check_hmac_response(chip, &buf, rc); tpm_buf_destroy(&buf); From patchwork Mon Apr 29 20:28:07 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647689 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E0FD815E5D5; Mon, 29 Apr 2024 20:31:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422667; cv=none; b=SkBAMd/RYAT58MKAakP1aN+i0rrMLzb/aD/YNR8SGJWs+dA6U0xOE3exWxME4TETCnrH9g7rOcELXoZjInsH8bMr80GdprhUnXcTI9+CTuOGRia+jX7kqtdvHZqDm5AFSabQbjJlTsl3I6nQD1T7Mi9sj5Rk0B1fRG5xzfqxSoY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422667; c=relaxed/simple; bh=Cko+6A+nnZkw5y/pYgGYflP0aP9gR/kov7SixeNqKaI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=sT7+vE6717nH+L8upHrXGyMP2/svEuj3WKSLDzHq/piV6yduvNHPARnK4gsrcCM+43XONWiH5C9FmutggNbqxzm0V7obY4cW3Y4W0wCpfDMXZ2GSqIXm3M89PQ7qZqZt5ePieIzyZpdhk7SkyLvRL7Ri9K7dPn1YHS5Yw4lEum4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=o7sLPYx6; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="o7sLPYx6" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422665; bh=Cko+6A+nnZkw5y/pYgGYflP0aP9gR/kov7SixeNqKaI=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=o7sLPYx6/yxOOlHm1izNCnGOuRa2DwlgWgkU4vxW9FZSQRigg3L7t6a3Op9Mz4M0a AvTDDeBghxm7WRZQUjIhbG0Vfw0Q4Ewsq/R+ygWyk26bOQ002KwQD79hhmpuV9Tkjx GKzt2K7iirj3nOXP3FCI9opPb0ZQ4lHBMfXlvNdI= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 8F2961281D87; Mon, 29 Apr 2024 16:31:05 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id CJvZj_ef_84z; Mon, 29 Apr 2024 16:31:05 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 051B912819F3; Mon, 29 Apr 2024 16:31:04 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 18/22] tpm: add session encryption protection to tpm2_get_random() Date: Mon, 29 Apr 2024 16:28:07 -0400 Message-Id: <20240429202811.13643-19-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 If some entity is snooping the TPM bus, they can see the random numbers we're extracting from the TPM and do prediction attacks against their consumers. Foil this attack by using response encryption to prevent the attacker from seeing the random sequence. Signed-off-by: James Bottomley Reviewed-by: Jarkko Sakkinen Reported-by: Nícolas F. R. A. Prado Signed-off-by: James Bottomley Acked-by: Ard Biesheuvel Reported-by: Nícolas F. R. A. Prado Acked-by: Ard Biesheuvel Signed-off-by: James Bottomley --- v7: add review --- drivers/char/tpm/tpm2-cmd.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c index a53a843294ed..0cdf892ec2a7 100644 --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -292,25 +292,35 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max) if (!num_bytes || max > TPM_MAX_RNG_DATA) return -EINVAL; - err = tpm_buf_init(&buf, 0, 0); + err = tpm2_start_auth_session(chip); if (err) return err; + err = tpm_buf_init(&buf, 0, 0); + if (err) { + tpm2_end_auth_session(chip); + return err; + } + do { - tpm_buf_reset(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_RANDOM); + tpm_buf_reset(&buf, TPM2_ST_SESSIONS, TPM2_CC_GET_RANDOM); + tpm_buf_append_hmac_session_opt(chip, &buf, TPM2_SA_ENCRYPT + | TPM2_SA_CONTINUE_SESSION, + NULL, 0); tpm_buf_append_u16(&buf, num_bytes); + tpm_buf_fill_hmac_session(chip, &buf); err = tpm_transmit_cmd(chip, &buf, offsetof(struct tpm2_get_random_out, buffer), "attempting get random"); + err = tpm_buf_check_hmac_response(chip, &buf, err); if (err) { if (err > 0) err = -EIO; goto out; } - out = (struct tpm2_get_random_out *) - &buf.data[TPM_HEADER_SIZE]; + out = (struct tpm2_get_random_out *)tpm_buf_parameters(&buf); recd = min_t(u32, be16_to_cpu(out->size), num_bytes); if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + @@ -327,9 +337,12 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max) } while (retries-- && total < max); tpm_buf_destroy(&buf); + tpm2_end_auth_session(chip); + return total ? total : -EIO; out: tpm_buf_destroy(&buf); + tpm2_end_auth_session(chip); return err; } From patchwork Mon Apr 29 20:28:08 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647690 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5646B15FA7F; Mon, 29 Apr 2024 20:31:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422677; cv=none; b=pfwt3H+lC7zJBfkwPmXgp/KdAHZ8yeEdpL/Iahr6cHrcT4JvlSYG/Dkfcuto4zRSnJOblFoUOJ1JyZ/rwbep9DYU3PS4LUz+YewYl+iHBIBHs84Xxx9EzsITQT2H3RJG9DH2fM6K3xOc+QVlFgEs28fRCR4jB8MtYT+G72+ExZ0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422677; c=relaxed/simple; bh=6IUNEBmlhflWLJpFrLT3K+7vWEsqVbgNlhzb83EUeUo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=bmbRKzymcWc7JRuSjH0UUN027z+8T70gBtYs4phk5k4p558uxfeG9lbAa9BeKlNQD80M43sKjDoJOEbPPRR8jUHdwnJV8gMtrXiUWVGlNmDpZpNt/pNgOAVIOb4KHWWioRu+/KGa0/JYF6D1YSYV32mSNVZiVIMb2NWE6LeBKXc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=KpBH3N53; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="KpBH3N53" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422674; bh=6IUNEBmlhflWLJpFrLT3K+7vWEsqVbgNlhzb83EUeUo=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=KpBH3N53BWn17EQje/gUfQ57vCBkoUyjXaEqe3V4D1SAfqsLqkLTudDkcy9Qid6t9 Tzdx3tCjATn5ZyOV1np9vpgPRMmhewxyi2fzfKBg/nS8pUOJ82XiWgS4lPodBeyInM FJgPzWG4j6QYKnqoSVq0dVJI8B+Y/3qNAe1VHA8Y= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id E2B111281ED0; Mon, 29 Apr 2024 16:31:14 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id 6eAB6ZeHLlSr; Mon, 29 Apr 2024 16:31:14 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 37E7D1281D87; Mon, 29 Apr 2024 16:31:14 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 19/22] KEYS: trusted: Add session encryption protection to the seal/unseal path Date: Mon, 29 Apr 2024 16:28:08 -0400 Message-Id: <20240429202811.13643-20-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 If some entity is snooping the TPM bus, the can see the data going in to be sealed and the data coming out as it is unsealed. Add parameter and response encryption to these cases to ensure that no secrets are leaked even if the bus is snooped. As part of doing this conversion it was discovered that policy sessions can't work with HMAC protected authority because of missing pieces (the tpm Nonce). I've added code to work the same way as before, which will result in potential authority exposure (while still adding security for the command and the returned blob), and a fixme to redo the API to get rid of this security hole. Signed-off-by: James Bottomley Reviewed-by: Jarkko Sakkinen --- v2: fix unseal with policy and password v3: fix session memory leak v7: add review --- security/keys/trusted-keys/trusted_tpm2.c | 88 ++++++++++++++++------- 1 file changed, 61 insertions(+), 27 deletions(-) diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c index 97b1dfca2dba..dfeec06301ce 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -253,26 +253,26 @@ int tpm2_seal_trusted(struct tpm_chip *chip, if (rc) return rc; + rc = tpm2_start_auth_session(chip); + if (rc) + goto out_put; + rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE); if (rc) { - tpm_put_ops(chip); - return rc; + tpm2_end_auth_session(chip); + goto out_put; } rc = tpm_buf_init_sized(&sized); if (rc) { tpm_buf_destroy(&buf); - tpm_put_ops(chip); - return rc; + tpm2_end_auth_session(chip); + goto out_put; } - tpm_buf_reset(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE); - tpm_buf_append_u32(&buf, options->keyhandle); - tpm2_buf_append_auth(&buf, TPM2_RS_PW, - NULL /* nonce */, 0, - 0 /* session_attributes */, - options->keyauth /* hmac */, - TPM_DIGEST_SIZE); + tpm_buf_append_name(chip, &buf, options->keyhandle, NULL); + tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_DECRYPT, + options->keyauth, TPM_DIGEST_SIZE); /* sensitive */ tpm_buf_append_u16(&sized, options->blobauth_len); @@ -314,10 +314,13 @@ int tpm2_seal_trusted(struct tpm_chip *chip, if (buf.flags & TPM_BUF_OVERFLOW) { rc = -E2BIG; + tpm2_end_auth_session(chip); goto out; } + tpm_buf_fill_hmac_session(chip, &buf); rc = tpm_transmit_cmd(chip, &buf, 4, "sealing data"); + rc = tpm_buf_check_hmac_response(chip, &buf, rc); if (rc) goto out; @@ -348,6 +351,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip, else payload->blob_len = blob_len; +out_put: tpm_put_ops(chip); return rc; } @@ -417,25 +421,31 @@ static int tpm2_load_cmd(struct tpm_chip *chip, if (blob_len > payload->blob_len) return -E2BIG; - rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD); + rc = tpm2_start_auth_session(chip); if (rc) return rc; - tpm_buf_append_u32(&buf, options->keyhandle); - tpm2_buf_append_auth(&buf, TPM2_RS_PW, - NULL /* nonce */, 0, - 0 /* session_attributes */, - options->keyauth /* hmac */, - TPM_DIGEST_SIZE); + rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD); + if (rc) { + tpm2_end_auth_session(chip); + return rc; + } + + tpm_buf_append_name(chip, &buf, options->keyhandle, NULL); + tpm_buf_append_hmac_session(chip, &buf, 0, options->keyauth, + TPM_DIGEST_SIZE); tpm_buf_append(&buf, blob, blob_len); if (buf.flags & TPM_BUF_OVERFLOW) { rc = -E2BIG; + tpm2_end_auth_session(chip); goto out; } + tpm_buf_fill_hmac_session(chip, &buf); rc = tpm_transmit_cmd(chip, &buf, 4, "loading blob"); + rc = tpm_buf_check_hmac_response(chip, &buf, rc); if (!rc) *blob_handle = be32_to_cpup( (__be32 *) &buf.data[TPM_HEADER_SIZE]); @@ -473,20 +483,44 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, u8 *data; int rc; - rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL); + rc = tpm2_start_auth_session(chip); if (rc) return rc; - tpm_buf_append_u32(&buf, blob_handle); - tpm2_buf_append_auth(&buf, - options->policyhandle ? - options->policyhandle : TPM2_RS_PW, - NULL /* nonce */, 0, - TPM2_SA_CONTINUE_SESSION, - options->blobauth /* hmac */, - options->blobauth_len); + rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL); + if (rc) { + tpm2_end_auth_session(chip); + return rc; + } + + tpm_buf_append_name(chip, &buf, blob_handle, NULL); + + if (!options->policyhandle) { + tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_ENCRYPT, + options->blobauth, + options->blobauth_len); + } else { + /* + * FIXME: The policy session was generated outside the + * kernel so we don't known the nonce and thus can't + * calculate a HMAC on it. Therefore, the user can + * only really use TPM2_PolicyPassword and we must + * send down the plain text password, which could be + * intercepted. We can still encrypt the returned + * key, but that's small comfort since the interposer + * could repeat our actions with the exfiltrated + * password. + */ + tpm2_buf_append_auth(&buf, options->policyhandle, + NULL /* nonce */, 0, 0, + options->blobauth, options->blobauth_len); + tpm_buf_append_hmac_session_opt(chip, &buf, TPM2_SA_ENCRYPT, + NULL, 0); + } + tpm_buf_fill_hmac_session(chip, &buf); rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing"); + rc = tpm_buf_check_hmac_response(chip, &buf, rc); if (rc > 0) rc = -EPERM; From patchwork Mon Apr 29 20:28:09 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647697 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5611C160884; Mon, 29 Apr 2024 20:31:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422684; cv=none; b=s6sV8+f3GM9/eQuVfds5Dn43X42U9yOYVhQc/HeB3dpsRmIxsc1jcpQ9AJre6j3L6MXpbjjZrVQz9zU8nligiaohOw51YuCPJdvtxBka70m1MaPD0+ukDE6whd7ofC+xNtav11qA+oHFS7sAWBpxSWSBu0hPkSd/syb+b63JQoM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422684; c=relaxed/simple; bh=JTFrQQ5rppx6jOZ9mbxK6nJZ7H2uf97pjMOLtahQVEU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Fbixt/oUl++WnLKud6ezVcaRqOvA74Hvu0A4M7LUdMb33hVLrDxb64IV8uM4kF1jmLQPdgxGEoxBmY5/fuAZXnX5tul9B8ABAUQObW3FjMNDn9c/jL+u4Hzqq2sSdGvvRQQkz8J8h6vcxWmhLh23VVfQoSwmcTYyiw6/Frg8V+w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=X/ZlulUb; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="X/ZlulUb" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422682; bh=JTFrQQ5rppx6jOZ9mbxK6nJZ7H2uf97pjMOLtahQVEU=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=X/ZlulUbr153RYI/WDPJJaD2KmC31eS3vFtp+XwFXL4M99LNs6TVfU6jC2WaK0GP2 zJ+rHa389sKIwAzVKYIDOla/7Vi3QKdi9mivdtPzFEAKq0WsK2aYh1/iyuN7pU2OzU kOXTT7yxsNQCEeo0rSIiciGQHfH6QISR6pXcH8UA= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id CA2CB1281D87; Mon, 29 Apr 2024 16:31:22 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id 4fNjZ6nT83Xe; Mon, 29 Apr 2024 16:31:22 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 389C612819F3; Mon, 29 Apr 2024 16:31:22 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 20/22] tpm: add the null key name as a sysfs export Date: Mon, 29 Apr 2024 16:28:09 -0400 Message-Id: <20240429202811.13643-21-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 This is the last component of encrypted tpm2 session handling that allows us to verify from userspace that the key derived from the NULL seed genuinely belongs to the TPM and has not been spoofed. The procedure for doing this involves creating an attestation identity key (which requires verification of the TPM EK certificate) and then using that AIK to sign a certification of the Elliptic Curve key over the NULL seed. Userspace must create this EC Key using the parameters prescribed in TCG TPM v2.0 Provisioning Guidance for the SRK ECC; if this is done correctly the names will match and the TPM can then run a TPM2_Certify operation on this derived primary key using the newly created AIK. Signed-off-by: James Bottomley Reviewed-by: Jarkko Sakkinen --- v6: change config name v7: add review --- drivers/char/tpm/tpm-sysfs.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c index 54c71473aa29..94231f052ea7 100644 --- a/drivers/char/tpm/tpm-sysfs.c +++ b/drivers/char/tpm/tpm-sysfs.c @@ -309,6 +309,21 @@ static ssize_t tpm_version_major_show(struct device *dev, } static DEVICE_ATTR_RO(tpm_version_major); +#ifdef CONFIG_TCG_TPM2_HMAC +static ssize_t null_name_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct tpm_chip *chip = to_tpm_chip(dev); + int size = TPM2_NAME_SIZE; + + bin2hex(buf, chip->null_key_name, size); + size *= 2; + buf[size++] = '\n'; + return size; +} +static DEVICE_ATTR_RO(null_name); +#endif + static struct attribute *tpm1_dev_attrs[] = { &dev_attr_pubek.attr, &dev_attr_pcrs.attr, @@ -326,6 +341,9 @@ static struct attribute *tpm1_dev_attrs[] = { static struct attribute *tpm2_dev_attrs[] = { &dev_attr_tpm_version_major.attr, +#ifdef CONFIG_TCG_TPM2_HMAC + &dev_attr_null_name.attr, +#endif NULL }; From patchwork Mon Apr 29 20:28:10 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647698 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A1D061635CC; Mon, 29 Apr 2024 20:31:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422693; cv=none; b=OaOgD6mmsma+BjRC8FSJNuDf+n1lCQqTy1o88PAj/xFWnyDBJp97hV0iDztqnObHviYJcq3o6o/TEYnDUQlnDnTMRh3QR5SUwTlia2zs6FIaV4gj3eYvC8TqqHXu6AXfouvoKCX9h1jEcCSPD0jGrmgoPpyEuFzRk7do/GW8U/M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422693; c=relaxed/simple; bh=+AcALnLhrxyTrreUNrnR/m4lugS1ce1ISYEJdO6iTjI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=umRS3aYc7L98t9mdYugrfmwDYJrSsz7Up2OzA8FnSkRh5cix080N97qvaKT5uW7mif1SzBaLoQUp0JXylyFHzwjsRQIeTLBmAh8pHAb9bXlCJv7S914BFIBiRdJcNPkKIZR5fYia9a1DE4YqTpbyAWCtFf4BiHtjxMYOG7A4Suc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=UdzN3HtF; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="UdzN3HtF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422691; bh=+AcALnLhrxyTrreUNrnR/m4lugS1ce1ISYEJdO6iTjI=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=UdzN3HtFcXu1zUiQNJCCoNWGLCk0TUUWpHXfbO7NjeRZNWh8jOrMWvJxgf6z2QlKz QuwpajX/8SgVK0RDgvX10Q8sGZsvRd7MiKCCptj2QdD8kwNKLcSMbKBIzf2G6Ox1NL A7BgegBV5qVF4cbWVJJUE9scqpldIRz+2TYpUD7g= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 174E012819F3; Mon, 29 Apr 2024 16:31:31 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id ES8C9BIFO3Kc; Mon, 29 Apr 2024 16:31:31 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 802031280AB2; Mon, 29 Apr 2024 16:31:30 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 21/22] Documentation: add tpm-security.rst Date: Mon, 29 Apr 2024 16:28:10 -0400 Message-Id: <20240429202811.13643-22-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Document how the new encrypted secure interface for TPM2 works and how security can be assured after boot by certifying the NULL seed. Signed-off-by: James Bottomley Reviewed-by: Jarkko Sakkinen --- v7: add review --- Documentation/security/tpm/tpm-security.rst | 216 ++++++++++++++++++++ 1 file changed, 216 insertions(+) create mode 100644 Documentation/security/tpm/tpm-security.rst diff --git a/Documentation/security/tpm/tpm-security.rst b/Documentation/security/tpm/tpm-security.rst new file mode 100644 index 000000000000..4f633f251033 --- /dev/null +++ b/Documentation/security/tpm/tpm-security.rst @@ -0,0 +1,216 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +TPM Security +============ + +The object of this document is to describe how we make the kernel's +use of the TPM reasonably robust in the face of external snooping and +packet alteration attacks (called passive and active interposer attack +in the literature). The current security document is for TPM 2.0. + +Introduction +------------ + +The TPM is usually a discrete chip attached to a PC via some type of +low bandwidth bus. There are exceptions to this such as the Intel +PTT, which is a software TPM running inside a software environment +close to the CPU, which are subject to different attacks, but right at +the moment, most hardened security environments require a discrete +hardware TPM, which is the use case discussed here. + +Snooping and Alteration Attacks against the bus +----------------------------------------------- + +The current state of the art for snooping the `TPM Genie`_ hardware +interposer which is a simple external device that can be installed in +a couple of seconds on any system or laptop. Recently attacks were +successfully demonstrated against the `Windows Bitlocker TPM`_ system. +Most recently the same `attack against TPM based Linux disk +encryption`_ schemes. The next phase of research seems to be hacking +existing devices on the bus to act as interposers, so the fact that +the attacker requires physical access for a few seconds might +evaporate. However, the goal of this document is to protect TPM +secrets and integrity as far as we are able in this environment and to +try to insure that if we can't prevent the attack then at least we can +detect it. + +Unfortunately, most of the TPM functionality, including the hardware +reset capability can be controlled by an attacker who has access to +the bus, so we'll discuss some of the disruption possibilities below. + +Measurement (PCR) Integrity +--------------------------- + +Since the attacker can send their own commands to the TPM, they can +send arbitrary PCR extends and thus disrupt the measurement system, +which would be an annoying denial of service attack. However, there +are two, more serious, classes of attack aimed at entities sealed to +trust measurements. + +1. The attacker could intercept all PCR extends coming from the system + and completely substitute their own values, producing a replay of + an untampered state that would cause PCR measurements to attest to + a trusted state and release secrets + +2. At some point in time the attacker could reset the TPM, clearing + the PCRs and then send down their own measurements which would + effectively overwrite the boot time measurements the TPM has + already done. + +The first can be thwarted by always doing HMAC protection of the PCR +extend and read command meaning measurement values cannot be +substituted without producing a detectable HMAC failure in the +response. However, the second can only really be detected by relying +on some sort of mechanism for protection which would change over TPM +reset. + +Secrets Guarding +---------------- + +Certain information passing in and out of the TPM, such as key sealing +and private key import and random number generation, is vulnerable to +interception which HMAC protection alone cannot protect against, so +for these types of command we must also employ request and response +encryption to prevent the loss of secret information. + +Establishing Initial Trust with the TPM +--------------------------------------- + +In order to provide security from the beginning, an initial shared or +asymmetric secret must be established which must also be unknown to +the attacker. The most obvious avenues for this are the endorsement +and storage seeds, which can be used to derive asymmetric keys. +However, using these keys is difficult because the only way to pass +them into the kernel would be on the command line, which requires +extensive support in the boot system, and there's no guarantee that +either hierarchy would not have some type of authorization. + +The mechanism chosen for the Linux Kernel is to derive the primary +elliptic curve key from the null seed using the standard storage seed +parameters. The null seed has two advantages: firstly the hierarchy +physically cannot have an authorization, so we are always able to use +it and secondly, the null seed changes across TPM resets, meaning if +we establish trust on the null seed at start of day, all sessions +salted with the derived key will fail if the TPM is reset and the seed +changes. + +Obviously using the null seed without any other prior shared secrets, +we have to create and read the initial public key which could, of +course, be intercepted and substituted by the bus interposer. +However, the TPM has a key certification mechanism (using the EK +endorsement certificate, creating an attestation identity key and +certifying the null seed primary with that key) which is too complex +to run within the kernel, so we keep a copy of the null primary key +name, which is what is exported via sysfs so user-space can run the +full certification when it boots. The definitive guarantee here is +that if the null primary key certifies correctly, you know all your +TPM transactions since start of day were secure and if it doesn't, you +know there's an interposer on your system (and that any secret used +during boot may have been leaked). + +Stacking Trust +-------------- + +In the current null primary scenario, the TPM must be completely +cleared before handing it on to the next consumer. However the kernel +hands to user-space the name of the derived null seed key which can +then be verified by certification in user-space. Therefore, this chain +of name handoff can be used between the various boot components as +well (via an unspecified mechanism). For instance, grub could use the +null seed scheme for security and hand the name off to the kernel in +the boot area. The kernel could make its own derivation of the key +and the name and know definitively that if they differ from the handed +off version that tampering has occurred. Thus it becomes possible to +chain arbitrary boot components together (UEFI to grub to kernel) via +the name handoff provided each successive component knows how to +collect the name and verifies it against its derived key. + +Session Properties +------------------ + +All TPM commands the kernel uses allow sessions. HMAC sessions may be +used to check the integrity of requests and responses and decrypt and +encrypt flags may be used to shield parameters and responses. The +HMAC and encryption keys are usually derived from the shared +authorization secret, but for a lot of kernel operations that is well +known (and usually empty). Thus, every HMAC session used by the +kernel must be created using the null primary key as the salt key +which thus provides a cryptographic input into the session key +derivation. Thus, the kernel creates the null primary key once (as a +volatile TPM handle) and keeps it around in a saved context stored in +tpm_chip for every in-kernel use of the TPM. Currently, because of a +lack of de-gapping in the in-kernel resource manager, the session must +be created and destroyed for each operation, but, in future, a single +session may also be reused for the in-kernel HMAC, encryption and +decryption sessions. + +Protection Types +---------------- + +For every in-kernel operation we use null primary salted HMAC to +protect the integrity. Additionally, we use parameter encryption to +protect key sealing and parameter decryption to protect key unsealing +and random number generation. + +Null Primary Key Certification in Userspace +=========================================== + +Every TPM comes shipped with a couple of X.509 certificates for the +primary endorsement key. This document assumes that the Elliptic +Curve version of the certificate exists at 01C00002, but will work +equally well with the RSA certificate (at 01C00001). + +The first step in the certification is primary creation using the +template from the `TCG EK Credential Profile`_ which allows comparison +of the generated primary key against the one in the certificate (the +public key must match). Note that generation of the EK primary +requires the EK hierarchy password, but a pre-generated version of the +EC primary should exist at 81010002 and a TPM2_ReadPublic() may be +performed on this without needing the key authority. Next, the +certificate itself must be verified to chain back to the manufacturer +root (which should be published on the manufacturer website). Once +this is done, an attestation key (AK) is generated within the TPM and +it's name and the EK public key can be used to encrypt a secret using +TPM2_MakeCredential. The TPM then runs TPM2_ActivateCredential which +will only recover the secret if the binding between the TPM, the EK +and the AK is true. the generated AK may now be used to run a +certification of the null primary key whose name the kernel has +exported. Since TPM2_MakeCredential/ActivateCredential are somewhat +complicated, a more simplified process involving an externally +generated private key is described below. + +This process is a simplified abbreviation of the usual privacy CA +based attestation process. The assumption here is that the +attestation is done by the TPM owner who thus has access to only the +owner hierarchy. The owner creates an external public/private key +pair (assume elliptic curve in this case) and wraps the private key +for import using an inner wrapping process and parented to the EC +derived storage primary. The TPM2_Import() is done using a parameter +decryption HMAC session salted to the EK primary (which also does not +require the EK key authority) meaning that the inner wrapping key is +the encrypted parameter and thus the TPM will not be able to perform +the import unless is possesses the certified EK so if the command +succeeds and the HMAC verifies on return we know we have a loadable +copy of the private key only for the certified TPM. This key is now +loaded into the TPM and the Storage primary flushed (to free up space +for the null key generation). + +The null EC primary is now generated using the Storage profile +outlined in the `TCG TPM v2.0 Provisioning Guidance`_; the name of +this key (the hash of the public area) is computed and compared to the +null seed name presented by the kernel in +/sys/class/tpm/tpm0/null_name. If the names do not match, the TPM is +compromised. If the names match, the user performs a TPM2_Certify() +using the null primary as the object handle and the loaded private key +as the sign handle and providing randomized qualifying data. The +signature of the returned certifyInfo is verified against the public +part of the loaded private key and the qualifying data checked to +prevent replay. If all of these tests pass, the user is now assured +that TPM integrity and privacy was preserved across the entire boot +sequence of this kernel. + +.. _TPM Genie: https://www.nccgroup.trust/globalassets/about-us/us/documents/tpm-genie.pdf +.. _Windows Bitlocker TPM: https://dolosgroup.io/blog/2021/7/9/from-stolen-laptop-to-inside-the-company-network +.. _attack against TPM based Linux disk encryption: https://www.secura.com/blog/tpm-sniffing-attacks-against-non-bitlocker-targets +.. _TCG EK Credential Profile: https://trustedcomputinggroup.org/resource/tcg-ek-credential-profile-for-tpm-family-2-0/ +.. _TCG TPM v2.0 Provisioning Guidance: https://trustedcomputinggroup.org/resource/tcg-tpm-v2-0-provisioning-guidance/ From patchwork Mon Apr 29 20:28:11 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 13647699 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C4ACA168B11; Mon, 29 Apr 2024 20:31:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422703; cv=none; b=qW8S7ocG9fLxgIFMKWa0CjNNS+OLjirNGJSB8ENVGEbm6DCAL3XAJgaW+lEjM+PWg0dizuUUy3saSlwuUCw/R2o/0OWxKIEaACgam+eAaXp6qr7EjC69PJvgZrGirb3l+zXlB9JxkX7jZ/l89kIB2Bj0UfDyHqPrrbqbZQUjv8M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714422703; c=relaxed/simple; bh=TCTQawSlwHMAHRI35VJYzOZgu+nzZlAXwDrbDxmmq7E=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=KLnYz9QwHw1Na4cXdqyzOr+ZjN9sM3UdaENC4T0sa6xLHMHjSL/dKuqjMdMmyfonPv+65rGeSb9VUu5RSvaoxmzscvnSITRBYWiXfAFlK7Cye08fzbPTSvsh3BUsmv7dP/eyTvQnbMAJrIMyuqhELz33U4WIasVSwTvZ06cSLtA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=rNno/PUx; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="rNno/PUx" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1714422701; bh=TCTQawSlwHMAHRI35VJYzOZgu+nzZlAXwDrbDxmmq7E=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=rNno/PUxIWfPvYods1pgxlxPD+pMoTcTPicBGuh7L9qlbjBChJmVZXDrjZgV5ywxd whp+/6WgqRYBrbCNbzE19WIVZygntgVz+YxZNrIss6X6ZKT85a1f2wtgYejggmW4b/ AxuGr96utWdhoRoj/IQPWVrot9UuP2V5/F/M9WCc= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 3A7C61281D87; Mon, 29 Apr 2024 16:31:41 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id hgPZm-lGzbaI; Mon, 29 Apr 2024 16:31:41 -0400 (EDT) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 4927A1280AB2; Mon, 29 Apr 2024 16:31:40 -0400 (EDT) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v8 22/22] tpm: disable the TPM if NULL name changes Date: Mon, 29 Apr 2024 16:28:11 -0400 Message-Id: <20240429202811.13643-23-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> References: <20240429202811.13643-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: keyrings@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Update tpm2_load_context() to return -EINVAL on integrity failures and use this as a signal when loading the NULL context that something might be wrong. If the signal fails, check the name of the NULL primary against the one stored in the chip data and if there is a mismatch disable the TPM because it is likely to have suffered a reset attack. Signed-off-by: James Bottomley --- drivers/char/tpm/tpm-chip.c | 3 ++ drivers/char/tpm/tpm2-sessions.c | 77 +++++++++++++++++++++++++------- drivers/char/tpm/tpm2-space.c | 3 ++ include/linux/tpm.h | 4 +- 4 files changed, 70 insertions(+), 17 deletions(-) diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index d93937326b2e..854546000c92 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -158,6 +158,9 @@ int tpm_try_get_ops(struct tpm_chip *chip) { int rc = -EIO; + if (chip->flags & TPM_CHIP_FLAG_DISABLE) + return rc; + get_device(&chip->dev); down_read(&chip->ops_sem); diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c index 3c97d3d5e00e..98819c9a0913 100644 --- a/drivers/char/tpm/tpm2-sessions.c +++ b/drivers/char/tpm/tpm2-sessions.c @@ -80,6 +80,9 @@ /* maximum number of names the TPM must remember for authorization */ #define AUTH_MAX_NAMES 3 +static int tpm2_create_primary(struct tpm_chip *chip, u32 hierarchy, + u32 *handle, u8 *name); + /* * This is the structure that carries all the auth information (like * session handle, nonces, session key and auth) from use to use it is @@ -851,6 +854,37 @@ static int tpm2_parse_start_auth_session(struct tpm2_auth *auth, return 0; } +static int tpm2_load_null(struct tpm_chip *chip, u32 *null_key) +{ + int rc; + unsigned int offset = 0; /* dummy offset for null seed context */ + u8 name[SHA256_DIGEST_SIZE + 2]; + + rc = tpm2_load_context(chip, chip->null_key_context, &offset, + null_key); + if (rc != -EINVAL) + return rc; + + /* an integrity failure may mean the TPM has been reset */ + dev_err(&chip->dev, "NULL key integrity failure!\n"); + /* check the null name against what we know */ + tpm2_create_primary(chip, TPM2_RH_NULL, NULL, name); + if (memcmp(name, chip->null_key_name, sizeof(name)) == 0) + /* name unchanged, assume transient integrity failure */ + return rc; + /* + * Fatal TPM failure: the NULL seed has actually changed, so + * the TPM must have been illegally reset. All in-kernel TPM + * operations will fail because the NULL primary can't be + * loaded to salt the sessions, but disable the TPM anyway so + * userspace programmes can't be compromised by it. + */ + dev_err(&chip->dev, "NULL name has changed, disabling TPM due to interference\n"); + chip->flags |= TPM_CHIP_FLAG_DISABLE; + + return rc; +} + /** * tpm2_start_auth_session() - create a HMAC authentication session with the TPM * @chip: the TPM chip structure to create the session with @@ -868,12 +902,9 @@ int tpm2_start_auth_session(struct tpm_chip *chip) struct tpm_buf buf; struct tpm2_auth *auth = chip->auth; int rc; - /* null seed context has no offset, but we must provide one */ - unsigned int offset = 0; - u32 nullkey; + u32 null_key; - rc = tpm2_load_context(chip, chip->null_key_context, &offset, - &nullkey); + rc = tpm2_load_null(chip, &null_key); if (rc) goto out; @@ -884,7 +915,7 @@ int tpm2_start_auth_session(struct tpm_chip *chip) goto out; /* salt key handle */ - tpm_buf_append_u32(&buf, nullkey); + tpm_buf_append_u32(&buf, null_key); /* bind key handle */ tpm_buf_append_u32(&buf, TPM2_RH_NULL); /* nonce caller */ @@ -908,7 +939,7 @@ int tpm2_start_auth_session(struct tpm_chip *chip) tpm_buf_append_u16(&buf, TPM_ALG_SHA256); rc = tpm_transmit_cmd(chip, &buf, 0, "start auth session"); - tpm2_flush_context(chip, nullkey); + tpm2_flush_context(chip, null_key); if (rc == TPM2_RC_SUCCESS) rc = tpm2_parse_start_auth_session(auth, &buf); @@ -930,19 +961,25 @@ EXPORT_SYMBOL(tpm2_start_auth_session); * @buf: The response buffer from the chip * @handle: pointer to be filled in with the return handle of the primary * @hierarchy: The hierarchy the primary was created for + * @name: pointer to be filled in with the primary key name * * @returns: 0 on success or a positive TPM or negative standard error */ static int tpm2_parse_create_primary(struct tpm_chip *chip, struct tpm_buf *buf, - u32 *handle, u32 hierarchy) + u32 *handle, u32 hierarchy, u8 *name) { struct tpm_header *head = (struct tpm_header *)buf->data; off_t offset_r = TPM_HEADER_SIZE, offset_t; u16 len = TPM_HEADER_SIZE; u32 total_len = be32_to_cpu(head->length); - u32 val, param_len; + u32 val, param_len, keyhandle; + + keyhandle = tpm_buf_read_u32(buf, &offset_r); + if (handle) + *handle = keyhandle; + else + tpm2_flush_context(chip, keyhandle); - *handle = tpm_buf_read_u32(buf, &offset_r); param_len = tpm_buf_read_u32(buf, &offset_r); /* * param_len doesn't include the header, but all the other @@ -955,9 +992,14 @@ static int tpm2_parse_create_primary(struct tpm_chip *chip, struct tpm_buf *buf, return -EINVAL; len = tpm_buf_read_u16(buf, &offset_r); offset_t = offset_r; - /* now we have the public area, compute the name of the object */ - put_unaligned_be16(TPM_ALG_SHA256, chip->null_key_name); - sha256(&buf->data[offset_r], len, chip->null_key_name + 2); + if (name) { + /* + * now we have the public area, compute the name of + * the object + */ + put_unaligned_be16(TPM_ALG_SHA256, name); + sha256(&buf->data[offset_r], len, name + 2); + } /* validate the public key */ val = tpm_buf_read_u16(buf, &offset_t); @@ -1086,6 +1128,7 @@ static int tpm2_parse_create_primary(struct tpm_chip *chip, struct tpm_buf *buf, * @chip: the TPM chip to create under * @hierarchy: The hierarchy handle to create under * @handle: The returned volatile handle on success + * @name: The name of the returned key * * For platforms that might not have a persistent primary, this can be * used to create one quickly on the fly (it uses Elliptic Curve not @@ -1097,7 +1140,7 @@ static int tpm2_parse_create_primary(struct tpm_chip *chip, struct tpm_buf *buf, * @returns: 0 on success or positive TPM or negative error. */ static int tpm2_create_primary(struct tpm_chip *chip, u32 hierarchy, - u32 *handle) + u32 *handle, u8 *name) { int rc; struct tpm_buf buf; @@ -1187,7 +1230,8 @@ static int tpm2_create_primary(struct tpm_chip *chip, u32 hierarchy, "attempting to create NULL primary"); if (rc == TPM2_RC_SUCCESS) - rc = tpm2_parse_create_primary(chip, &buf, handle, hierarchy); + rc = tpm2_parse_create_primary(chip, &buf, handle, hierarchy, + name); tpm_buf_destroy(&buf); @@ -1199,7 +1243,8 @@ static int tpm2_create_null_primary(struct tpm_chip *chip) u32 null_key; int rc; - rc = tpm2_create_primary(chip, TPM2_RH_NULL, &null_key); + rc = tpm2_create_primary(chip, TPM2_RH_NULL, &null_key, + chip->null_key_name); if (rc == TPM2_RC_SUCCESS) { unsigned int offset = 0; /* dummy offset for null key context */ diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c index 24479a81c23c..4892d491da8d 100644 --- a/drivers/char/tpm/tpm2-space.c +++ b/drivers/char/tpm/tpm2-space.c @@ -105,6 +105,9 @@ int tpm2_load_context(struct tpm_chip *chip, u8 *buf, *handle = 0; tpm_buf_destroy(&tbuf); return -ENOENT; + } else if (tpm2_rc_value(rc) == TPM2_RC_INTEGRITY) { + tpm_buf_destroy(&tbuf); + return -EINVAL; } else if (rc > 0) { dev_warn(&chip->dev, "%s: failed with a TPM error 0x%04X\n", __func__, rc); diff --git a/include/linux/tpm.h b/include/linux/tpm.h index dd4d6a6158c4..c17e4efbb2e5 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -248,6 +248,7 @@ enum tpm2_return_codes { TPM2_RC_SUCCESS = 0x0000, TPM2_RC_HASH = 0x0083, /* RC_FMT1 */ TPM2_RC_HANDLE = 0x008B, + TPM2_RC_INTEGRITY = 0x009F, TPM2_RC_INITIALIZE = 0x0100, /* RC_VER1 */ TPM2_RC_FAILURE = 0x0101, TPM2_RC_DISABLED = 0x0120, @@ -346,6 +347,7 @@ enum tpm_chip_flags { TPM_CHIP_FLAG_FIRMWARE_UPGRADE = BIT(7), TPM_CHIP_FLAG_SUSPENDED = BIT(8), TPM_CHIP_FLAG_HWRNG_DISABLED = BIT(9), + TPM_CHIP_FLAG_DISABLE = BIT(10), }; #define to_tpm_chip(d) container_of(d, struct tpm_chip, dev) @@ -447,7 +449,7 @@ static inline bool tpm_is_firmware_upgrade(struct tpm_chip *chip) static inline u32 tpm2_rc_value(u32 rc) { - return (rc & BIT(7)) ? rc & 0xff : rc; + return (rc & BIT(7)) ? rc & 0xbf : rc; } #if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE)